diff --git a/src/cascadia/TerminalApp/ColorHelper.cpp b/src/cascadia/TerminalApp/ColorHelper.cpp
deleted file mode 100644
index 2235cc6b37..0000000000
--- a/src/cascadia/TerminalApp/ColorHelper.cpp
+++ /dev/null
@@ -1,267 +0,0 @@
-#include "ColorHelper.h"
-
-using namespace winrt::TerminalApp;
-
-// Method Description:
-// Determines whether or not a given color is light
-// Arguments:
-// - color: this color is going to be examined whether it
-// is light or not
-// Return Value:
-// - true if light, false if dark
-bool ColorHelper::IsBrightColor(const winrt::Windows::UI::Color& color)
-{
-    // https://www.w3.org/TR/AERT#color-contrast
-    auto brightness = (color.R * 299 + color.G * 587 + color.B * 114) / 1000.f;
-    return brightness > 128.f;
-}
-
-// Method Description:
-// Converts a rgb color to an hsl one
-// Arguments:
-// - color: the rgb color, which is going to be converted
-// Return Value:
-// - a hsl color with the following ranges
-//      - H: [0.f -360.f]
-//      - L: [0.f - 1.f] (rounded to the third decimal place)
-//      - S: [0.f - 1.f] (rounded to the third decimal place)
-HSL ColorHelper::RgbToHsl(const winrt::Windows::UI::Color& color)
-{
-    // https://www.rapidtables.com/convert/color/rgb-to-hsl.html
-    auto epsilon = std::numeric_limits<float>::epsilon();
-    auto r = color.R / 255.f;
-    auto g = color.G / 255.f;
-    auto b = color.B / 255.f;
-
-    auto max = std::max(r, std::max(g, b));
-    auto min = std::min(r, std::min(g, b));
-
-    auto delta = max - min;
-
-    auto h = 0.f;
-    auto s = 0.f;
-    auto l = (max + min) / 2;
-
-    if (delta < epsilon || max < epsilon) /* delta == 0 || max == 0*/
-    {
-        l = std::roundf(l * 1000) / 1000;
-        return HSL{ h, s, l };
-    }
-
-    s = l > 0.5 ? delta / (2 - max - min) : delta / (max + min);
-
-    if (max - r < epsilon) // max == r
-    {
-        h = (g - b) / delta + (g < b ? 6 : 0);
-    }
-    else if (max - g < epsilon) // max == g
-    {
-        h = (b - r) / delta + 2;
-    }
-    else if (max - b < epsilon) // max == b
-    {
-        h = (r - g) / delta + 4;
-    }
-
-    // three decimal places after the comma ought
-    // to be enough for everybody - Bill Gates, 1981
-    auto finalH = std::roundf(h * 60);
-    auto finalS = std::roundf(s * 1000) / 1000;
-    auto finalL = std::roundf(l * 1000) / 1000;
-
-    return HSL{ finalH, finalS, finalL };
-}
-
-// Method Description:
-// Converts a hsl color to rgb one
-// Arguments:
-// - color: the hsl color, which is going to be converted
-// Return Value:
-// - the rgb color (r,g,b - [0, 255] range)
-winrt::Windows::UI::Color ColorHelper::HslToRgb(const HSL& color)
-{
-    auto epsilon = std::numeric_limits<float>::epsilon();
-
-    auto h = (color.H - 1.f > epsilon) ? color.H / 360.f : color.H;
-    auto s = (color.S - 1.f > epsilon) ? color.S / 100.f : color.S;
-    auto l = (color.L - 1.f > epsilon) ? color.L / 100.f : color.L;
-
-    auto r = l;
-    auto g = l;
-    auto b = l;
-
-    if (s > epsilon)
-    {
-        auto q = l < 0.5 ? l * (1 + s) : l + s - l * s;
-        auto p = 2 * l - q;
-        r = HueToRgb(p, q, h + 1.f / 3.f);
-        g = HueToRgb(p, q, h);
-        b = HueToRgb(p, q, h - 1.f / 3.f);
-    }
-
-    auto finalR = static_cast<uint8_t>(std::roundf(r * 255));
-    auto finalG = static_cast<uint8_t>(std::roundf(g * 255));
-    auto finalB = static_cast<uint8_t>(std::roundf(b * 255));
-    uint8_t finalA = 255; //opaque
-
-    return winrt::Windows::UI::ColorHelper::FromArgb(finalA, finalR, finalG, finalB);
-}
-
-float ColorHelper::HueToRgb(float p, float q, float t)
-{
-    auto epsilon = std::numeric_limits<float>::epsilon();
-
-    if (t < 0)
-        t += 1;
-    if (t > 1)
-        t -= 1;
-    if (t - (1.f / 6.f) < epsilon)
-        return p + (q - p) * 6 * t;
-    if (t - .5f < epsilon)
-        return q;
-    if (t - 2.f / 3.f < epsilon)
-        return p + (q - p) * (2.f / 3.f - t) * 6;
-    return p;
-}
-
-// Method Description:
-// Lightens a color by a given amount
-// Arguments:
-// - color: the color which is going to be lightened
-// - amount: the lighten amount (0-100)
-// Return Value:
-// - the lightened color in RGB format
-winrt::Windows::UI::Color ColorHelper::Lighten(const winrt::Windows::UI::Color& color, float amount /* = 10.f*/)
-{
-    auto hsl = RgbToHsl(color);
-    hsl.L += amount / 100;
-    hsl.L = std::clamp(hsl.L, 0.f, 1.f);
-    return HslToRgb(hsl);
-}
-
-// Method Description:
-// Darkens a color by a given amount
-// Arguments:
-// - color: the color which is going to be darkened
-// - amount: the darken amount (0-100)
-// Return Value:
-// - the darkened color in RGB format
-winrt::Windows::UI::Color ColorHelper::Darken(const winrt::Windows::UI::Color& color, float amount /* = 10.f*/)
-{
-    auto hsl = RgbToHsl(color);
-    hsl.L -= amount / 100;
-    hsl.L = std::clamp(hsl.L, 0.f, 1.f);
-    return HslToRgb(hsl);
-}
-
-// Method Description:
-// Gets an accent color to a given color. Basically, generates
-// 16 shades of the color and finds the first which has a good
-// contrast according to https://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef (WCAG Version 2)
-// Readability ratio of 3.5 seems to look quite nicely
-// Arguments:
-// - color: the color for which we need an accent
-// Return Value:
-// - the accent color in RGB format
-winrt::Windows::UI::Color ColorHelper::GetAccentColor(const winrt::Windows::UI::Color& color)
-{
-    auto accentColor = RgbToHsl(color);
-
-    if (accentColor.S < 0.15)
-    {
-        accentColor.S = 0.15f;
-    }
-
-    constexpr auto shadeCount = 16;
-    constexpr auto shadeStep = 1.f / shadeCount;
-    auto shades = std::map<float, HSL>();
-    for (auto i = 0; i < 15; i++)
-    {
-        auto shade = HSL{ accentColor.H, accentColor.S, i * shadeStep };
-        auto contrast = GetReadability(shade, accentColor);
-        shades.insert(std::make_pair(contrast, shade));
-    }
-
-    // 3f is quite nice if the whole non-client area is painted
-    constexpr auto readability = 1.75f;
-    for (auto shade : shades)
-    {
-        if (shade.first >= readability)
-        {
-            return HslToRgb(shade.second);
-        }
-    }
-    return HslToRgb(shades.end()->second);
-}
-
-// Method Description:
-// Gets the readability of two colors according to
-// https://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef (WCAG Version 2)
-// Arguments:
-// - firstColor: the first color for the readability check (hsl)
-// - secondColor: the second color for the readability check (hsl)
-// Return Value:
-// - the readability of the colors according to (WCAG Version 2)
-float ColorHelper::GetReadability(const HSL& first, const HSL& second)
-{
-    return GetReadability(HslToRgb(first), HslToRgb(second));
-}
-
-// Method Description:
-// Gets the readability of two colors according to
-// https://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef (WCAG Version 2)
-// Arguments:
-// - firstColor: the first color for the readability check (rgb)
-// - secondColor: the second color for the readability check (rgb)
-// Return Value:
-// - the readability of the colors according to (WCAG Version 2)
-float ColorHelper::GetReadability(const winrt::Windows::UI::Color& first, const winrt::Windows::UI::Color& second)
-{
-    auto l1 = GetLuminance(first);
-    auto l2 = GetLuminance(second);
-
-    return (std::max(l1, l2) + 0.05f) / std::min(l1, l2) + 0.05f;
-}
-
-// Method Description:
-// Calculates the luminance of a given color according to
-// https://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef
-// Arguments:
-// - color: its luminance is going to be calculated
-// Return Value:
-// - the luminance of the color
-float ColorHelper::GetLuminance(const winrt::Windows::UI::Color& color)
-{
-    auto epsilon = std::numeric_limits<float>::epsilon();
-    float R, G, B;
-    auto RsRGB = color.R / 255.f;
-    auto GsRGB = color.G / 255.f;
-    auto BsRGB = color.B / 255.f;
-
-    if (RsRGB - 0.03928f <= epsilon)
-    {
-        R = RsRGB / 12.92f;
-    }
-    else
-    {
-        R = std::pow(((RsRGB + 0.055f) / 1.055f), 2.4f);
-    }
-    if (GsRGB - 0.03928f <= epsilon)
-    {
-        G = GsRGB / 12.92f;
-    }
-    else
-    {
-        G = std::pow(((GsRGB + 0.055f) / 1.055f), 2.4f);
-    }
-    if (BsRGB - 0.03928f <= epsilon)
-    {
-        B = BsRGB / 12.92f;
-    }
-    else
-    {
-        B = std::pow(((BsRGB + 0.055f) / 1.055f), 2.4f);
-    }
-    auto luminance = (0.2126f * R) + (0.7152f * G) + (0.0722f * B);
-    return std::roundf(luminance * 10000) / 10000.f;
-}
diff --git a/src/cascadia/TerminalApp/ColorHelper.h b/src/cascadia/TerminalApp/ColorHelper.h
deleted file mode 100644
index e4ab3f42b7..0000000000
--- a/src/cascadia/TerminalApp/ColorHelper.h
+++ /dev/null
@@ -1,31 +0,0 @@
-#pragma once
-
-#include <winrt/Windows.UI.h>
-
-namespace winrt::TerminalApp
-{
-    class HSL
-    {
-    public:
-        float H;
-        float S;
-        float L;
-    };
-
-    class ColorHelper
-    {
-    public:
-        static bool IsBrightColor(const Windows::UI::Color& color);
-        static HSL RgbToHsl(const Windows::UI::Color& color);
-        static Windows::UI::Color HslToRgb(const HSL& color);
-        static Windows::UI::Color Lighten(const Windows::UI::Color& color, float amount = 10.f);
-        static Windows::UI::Color Darken(const Windows::UI::Color& color, float amount = 10.f);
-        static Windows::UI::Color GetAccentColor(const Windows::UI::Color& color);
-        static float GetLuminance(const Windows::UI::Color& color);
-        static float GetReadability(const Windows::UI::Color& first, const Windows::UI::Color& second);
-        static float GetReadability(const HSL& first, const HSL& second);
-
-    private:
-        static float HueToRgb(float p, float q, float t);
-    };
-}
diff --git a/src/cascadia/TerminalApp/Tab.cpp b/src/cascadia/TerminalApp/Tab.cpp
index 6c305c66d1..b08842e3f2 100644
--- a/src/cascadia/TerminalApp/Tab.cpp
+++ b/src/cascadia/TerminalApp/Tab.cpp
@@ -8,8 +8,8 @@
 #include "SettingsPaneContent.h"
 #include "Tab.g.cpp"
 #include "Utils.h"
-#include "ColorHelper.h"
 #include "AppLogic.h"
+#include "../../types/inc/ColorFix.hpp"
 
 using namespace winrt;
 using namespace winrt::Windows::UI::Xaml;
@@ -2275,11 +2275,13 @@ namespace winrt::TerminalApp::implementation
     // the background color
     // - This method should only be called on the UI thread.
     // Arguments:
-    // - color: the color the user picked for their tab
+    // - uiColor: the color the user picked for their tab
     // Return Value:
     // - <none>
-    void Tab::_ApplyTabColorOnUIThread(const winrt::Windows::UI::Color& color)
+    void Tab::_ApplyTabColorOnUIThread(const winrt::Windows::UI::Color& uiColor)
     {
+        constexpr auto lightnessThreshold = 0.6f;
+        const til::color color{ uiColor };
         Media::SolidColorBrush selectedTabBrush{};
         Media::SolidColorBrush deselectedTabBrush{};
         Media::SolidColorBrush fontBrush{};
@@ -2292,7 +2294,7 @@ namespace winrt::TerminalApp::implementation
         // calculate the luminance of the current color and select a font
         // color based on that
         // see https://www.w3.org/TR/WCAG20/#relativeluminancedef
-        if (TerminalApp::ColorHelper::IsBrightColor(color))
+        if (ColorFix::GetLightness(color) >= lightnessThreshold)
         {
             auto subtleFillColorSecondary = winrt::Windows::UI::Colors::Black();
             subtleFillColorSecondary.A = 0x09;
@@ -2312,8 +2314,8 @@ namespace winrt::TerminalApp::implementation
         }
 
         // The tab font should be based on the evaluated appearance of the tab color layered on tab row.
-        const auto layeredTabColor = til::color{ color }.layer_over(_tabRowColor);
-        if (TerminalApp::ColorHelper::IsBrightColor(layeredTabColor))
+        const auto layeredTabColor = color.layer_over(_tabRowColor);
+        if (ColorFix::GetLightness(layeredTabColor) >= lightnessThreshold)
         {
             fontBrush.Color(winrt::Windows::UI::Colors::Black());
             auto secondaryFontColor = winrt::Windows::UI::Colors::Black();
@@ -2333,8 +2335,7 @@ namespace winrt::TerminalApp::implementation
         selectedTabBrush.Color(color);
 
         // Start with the current tab color, set to Opacity=.3
-        til::color deselectedTabColor{ color };
-        deselectedTabColor = deselectedTabColor.with_alpha(77); // 255 * .3 = 77
+        auto deselectedTabColor = color.with_alpha(77); // 255 * .3 = 77
 
         // If we DON'T have a color set from the color picker, or the profile's
         // tabColor, but we do have a unfocused color in the theme, use the
@@ -2376,7 +2377,7 @@ namespace winrt::TerminalApp::implementation
         // We don't want that to result in white text on a white tab row for
         // inactive tabs.
         const auto deselectedActualColor = deselectedTabColor.layer_over(_tabRowColor);
-        if (TerminalApp::ColorHelper::IsBrightColor(deselectedActualColor))
+        if (ColorFix::GetLightness(deselectedActualColor) >= lightnessThreshold)
         {
             deselectedFontBrush.Color(winrt::Windows::UI::Colors::Black());
         }
diff --git a/src/cascadia/TerminalApp/TabManagement.cpp b/src/cascadia/TerminalApp/TabManagement.cpp
index b7a3e29e5a..bbb42e8b7b 100644
--- a/src/cascadia/TerminalApp/TabManagement.cpp
+++ b/src/cascadia/TerminalApp/TabManagement.cpp
@@ -18,7 +18,6 @@
 #include <LibraryResources.h>
 
 #include "TabRowControl.h"
-#include "ColorHelper.h"
 #include "DebugTapConnection.h"
 #include "..\TerminalSettingsModel\FileUtils.h"
 
diff --git a/src/cascadia/TerminalApp/TerminalAppLib.vcxproj b/src/cascadia/TerminalApp/TerminalAppLib.vcxproj
index 7e5028167b..3be78cbce0 100644
--- a/src/cascadia/TerminalApp/TerminalAppLib.vcxproj
+++ b/src/cascadia/TerminalApp/TerminalAppLib.vcxproj
@@ -134,7 +134,6 @@
     <ClInclude Include="FilteredCommand.h" />
     <ClInclude Include="Pane.h" />
     <ClInclude Include="fzf/fzf.h" />
-    <ClInclude Include="ColorHelper.h" />
     <ClInclude Include="pch.h" />
     <ClInclude Include="ShortcutActionDispatch.h">
       <DependentUpon>ShortcutActionDispatch.idl</DependentUpon>
@@ -247,9 +246,6 @@
     <ClCompile Include="FilteredCommand.cpp" />
     <ClCompile Include="Pane.cpp" />
     <ClCompile Include="Pane.LayoutSizeNode.cpp" />
-    <ClCompile Include="ColorHelper.cpp">
-      <PrecompiledHeader>NotUsing</PrecompiledHeader>
-    </ClCompile>
     <ClCompile Include="DebugTapConnection.cpp" />
     <ClCompile Include="pch.cpp">
       <PrecompiledHeader>Create</PrecompiledHeader>
diff --git a/src/cascadia/TerminalApp/TerminalAppLib.vcxproj.filters b/src/cascadia/TerminalApp/TerminalAppLib.vcxproj.filters
index 68c7f8c7a3..d082b2a054 100644
--- a/src/cascadia/TerminalApp/TerminalAppLib.vcxproj.filters
+++ b/src/cascadia/TerminalApp/TerminalAppLib.vcxproj.filters
@@ -20,7 +20,6 @@
     </ClCompile>
     <ClCompile Include="AppCommandlineArgs.cpp" />
     <ClCompile Include="Commandline.cpp" />
-    <ClCompile Include="ColorHelper.cpp" />
     <ClCompile Include="DebugTapConnection.cpp" />
     <ClCompile Include="Jumplist.cpp" />
     <ClCompile Include="FilteredCommand.cpp">
@@ -48,7 +47,6 @@
     <ClInclude Include="AppCommandlineArgs.h" />
     <ClInclude Include="Commandline.h" />
     <ClInclude Include="DebugTapConnection.h" />
-    <ClInclude Include="ColorHelper.h" />
     <ClInclude Include="Jumplist.h" />
     <ClInclude Include="FilteredCommand.h">
       <Filter>commandPalette</Filter>
diff --git a/src/cascadia/TerminalApp/TerminalPage.cpp b/src/cascadia/TerminalApp/TerminalPage.cpp
index ce8e8762e4..7ee4649801 100644
--- a/src/cascadia/TerminalApp/TerminalPage.cpp
+++ b/src/cascadia/TerminalApp/TerminalPage.cpp
@@ -6,24 +6,24 @@
 #include "TerminalPage.h"
 
 #include <LibraryResources.h>
-#include <TerminalCore/ControlKeyStates.hpp>
 #include <Utils.h>
+#include <TerminalCore/ControlKeyStates.hpp>
 
-#include "../../types/inc/utils.hpp"
 #include "App.h"
-#include "ColorHelper.h"
 #include "DebugTapConnection.h"
-#include "SettingsPaneContent.h"
-#include "ScratchpadContent.h"
-#include "SnippetsPaneContent.h"
 #include "MarkdownPaneContent.h"
-#include "TabRowControl.h"
 #include "Remoting.h"
+#include "ScratchpadContent.h"
+#include "SettingsPaneContent.h"
+#include "SnippetsPaneContent.h"
+#include "TabRowControl.h"
+#include "../../types/inc/ColorFix.hpp"
+#include "../../types/inc/utils.hpp"
 
-#include "TerminalPage.g.cpp"
+#include "LaunchPositionRequest.g.cpp"
 #include "RenameWindowRequestedArgs.g.cpp"
 #include "RequestMoveContentArgs.g.cpp"
-#include "LaunchPositionRequest.g.cpp"
+#include "TerminalPage.g.cpp"
 
 using namespace winrt;
 using namespace winrt::Microsoft::Management::Deployment;
@@ -3904,36 +3904,18 @@ namespace winrt::TerminalApp::implementation
     //                and the non-client are behind it
     // Return Value:
     // - <none>
-    void TerminalPage::_SetNewTabButtonColor(const Windows::UI::Color& color, const Windows::UI::Color& accentColor)
+    void TerminalPage::_SetNewTabButtonColor(const til::color color, const til::color accentColor)
     {
+        constexpr auto lightnessThreshold = 0.6f;
         // TODO GH#3327: Look at what to do with the tab button when we have XAML theming
-        auto IsBrightColor = ColorHelper::IsBrightColor(color);
-        auto isLightAccentColor = ColorHelper::IsBrightColor(accentColor);
-        winrt::Windows::UI::Color pressedColor{};
-        winrt::Windows::UI::Color hoverColor{};
-        winrt::Windows::UI::Color foregroundColor{};
-        const auto hoverColorAdjustment = 5.f;
-        const auto pressedColorAdjustment = 7.f;
+        const auto IsBrightColor = ColorFix::GetLightness(color) >= lightnessThreshold;
+        const auto isLightAccentColor = ColorFix::GetLightness(accentColor) >= lightnessThreshold;
+        const auto hoverColorAdjustment = isLightAccentColor ? -0.05f : 0.05f;
+        const auto pressedColorAdjustment = isLightAccentColor ? -0.1f : 0.1f;
 
-        if (IsBrightColor)
-        {
-            foregroundColor = winrt::Windows::UI::Colors::Black();
-        }
-        else
-        {
-            foregroundColor = winrt::Windows::UI::Colors::White();
-        }
-
-        if (isLightAccentColor)
-        {
-            hoverColor = ColorHelper::Darken(accentColor, hoverColorAdjustment);
-            pressedColor = ColorHelper::Darken(accentColor, pressedColorAdjustment);
-        }
-        else
-        {
-            hoverColor = ColorHelper::Lighten(accentColor, hoverColorAdjustment);
-            pressedColor = ColorHelper::Lighten(accentColor, pressedColorAdjustment);
-        }
+        const auto foregroundColor = IsBrightColor ? Colors::Black() : Colors::White();
+        const auto hoverColor = til::color{ ColorFix::AdjustLightness(accentColor, hoverColorAdjustment) };
+        const auto pressedColor = til::color{ ColorFix::AdjustLightness(accentColor, pressedColorAdjustment) };
 
         Media::SolidColorBrush backgroundBrush{ accentColor };
         Media::SolidColorBrush backgroundHoverBrush{ hoverColor };
diff --git a/src/cascadia/TerminalApp/TerminalPage.h b/src/cascadia/TerminalApp/TerminalPage.h
index e4bf6efa1e..23def359b2 100644
--- a/src/cascadia/TerminalApp/TerminalPage.h
+++ b/src/cascadia/TerminalApp/TerminalPage.h
@@ -463,7 +463,7 @@ namespace winrt::TerminalApp::implementation
 
         void _RefreshUIForSettingsReload();
 
-        void _SetNewTabButtonColor(const Windows::UI::Color& color, const Windows::UI::Color& accentColor);
+        void _SetNewTabButtonColor(til::color color, til::color accentColor);
         void _ClearNewTabButtonColor();
 
         safe_void_coroutine _CompleteInitialization();
diff --git a/src/cascadia/TerminalApp/TitlebarControl.cpp b/src/cascadia/TerminalApp/TitlebarControl.cpp
index 1ed82f39ca..7ecf34d2c1 100644
--- a/src/cascadia/TerminalApp/TitlebarControl.cpp
+++ b/src/cascadia/TerminalApp/TitlebarControl.cpp
@@ -7,8 +7,7 @@
 #include "pch.h"
 
 #include "TitlebarControl.h"
-
-#include "ColorHelper.h"
+#include "../../types/inc/ColorFix.hpp"
 
 #include "TitlebarControl.g.cpp"
 
@@ -189,7 +188,8 @@ namespace winrt::TerminalApp::implementation
             return;
         }
 
-        const auto isBrightColor = ColorHelper::IsBrightColor(c);
+        constexpr auto lightnessThreshold = 0.6f;
+        const auto isBrightColor = ColorFix::GetLightness(c) >= lightnessThreshold;
         MinMaxCloseControl().RequestedTheme(isBrightColor ? winrt::Windows::UI::Xaml::ElementTheme::Light :
                                                             winrt::Windows::UI::Xaml::ElementTheme::Dark);
     }
diff --git a/src/cascadia/ut_app/ColorHelperTests.cpp b/src/cascadia/ut_app/ColorHelperTests.cpp
deleted file mode 100644
index 03ec18d57e..0000000000
--- a/src/cascadia/ut_app/ColorHelperTests.cpp
+++ /dev/null
@@ -1,130 +0,0 @@
-// Copyright (c) Microsoft Corporation.
-// Licensed under the MIT license.
-
-#include "precomp.h"
-
-#include "../TerminalSettingsModel/Profile.h"
-#include "../TerminalApp/ColorHelper.h"
-
-// Import some templates to compare floats using approximate matching.
-#include <consoletaeftemplates.hpp>
-
-using namespace Microsoft::Console;
-using namespace winrt::TerminalApp;
-using namespace WEX::Logging;
-using namespace WEX::TestExecution;
-using namespace WEX::Common;
-
-namespace TerminalAppUnitTests
-{
-    class ColorHelperTests
-    {
-        BEGIN_TEST_CLASS(ColorHelperTests)
-            TEST_CLASS_PROPERTY(L"ActivationContext", L"TerminalApp.Unit.Tests.manifest")
-        END_TEST_CLASS()
-
-        TEST_METHOD(ConvertRgbToHsl);
-        TEST_METHOD(ConvertHslToRgb);
-        TEST_METHOD(LuminanceTests);
-    };
-
-    void ColorHelperTests::ConvertHslToRgb()
-    {
-        auto red = winrt::Windows::UI::Colors::Red();
-        auto redHsl = ColorHelper::RgbToHsl(red);
-        VERIFY_ARE_EQUAL(0.f, redHsl.H);
-        VERIFY_ARE_EQUAL(1.f, redHsl.S);
-        VERIFY_ARE_EQUAL(0.5f, redHsl.L);
-
-        auto green = winrt::Windows::UI::Colors::Lime();
-        auto greenHsl = ColorHelper::RgbToHsl(green);
-        VERIFY_ARE_EQUAL(120.f, greenHsl.H);
-        VERIFY_ARE_EQUAL(1.f, greenHsl.S);
-        VERIFY_ARE_EQUAL(0.5f, greenHsl.L);
-
-        auto blue = winrt::Windows::UI::Colors::Blue();
-        auto blueHsl = ColorHelper::RgbToHsl(blue);
-        VERIFY_ARE_EQUAL(240.f, blueHsl.H);
-        VERIFY_ARE_EQUAL(1.f, blueHsl.S);
-        VERIFY_ARE_EQUAL(0.5f, blueHsl.L);
-
-        auto darkTurquoise = winrt::Windows::UI::Colors::DarkTurquoise();
-        auto darkTurquoiseHsl = ColorHelper::RgbToHsl(darkTurquoise);
-        VERIFY_ARE_EQUAL(181.f, darkTurquoiseHsl.H);
-        VERIFY_ARE_EQUAL(1.f, darkTurquoiseHsl.S);
-        VERIFY_ARE_EQUAL(0.41f, darkTurquoiseHsl.L);
-
-        auto darkViolet = winrt::Windows::UI::Colors::DarkViolet();
-        auto darkVioletHsl = ColorHelper::RgbToHsl(darkViolet);
-        VERIFY_ARE_EQUAL(282.f, darkVioletHsl.H);
-        VERIFY_ARE_EQUAL(1.f, darkVioletHsl.S);
-        VERIFY_ARE_EQUAL(0.414f, darkVioletHsl.L);
-
-        auto white = winrt::Windows::UI::Colors::White();
-        auto whiteHsl = ColorHelper::RgbToHsl(white);
-        VERIFY_ARE_EQUAL(0.f, whiteHsl.H);
-        VERIFY_ARE_EQUAL(0.f, whiteHsl.S);
-        VERIFY_ARE_EQUAL(1.f, whiteHsl.L);
-
-        auto black = winrt::Windows::UI::Colors::Black();
-        auto blackHsl = ColorHelper::RgbToHsl(black);
-        VERIFY_ARE_EQUAL(0.f, blackHsl.H);
-        VERIFY_ARE_EQUAL(0.f, blackHsl.S);
-        VERIFY_ARE_EQUAL(0.f, blackHsl.L);
-    }
-
-    void ColorHelperTests::ConvertRgbToHsl()
-    {
-        auto redHsl = HSL{ 0.f, 100.f, 50.f };
-        auto red = ColorHelper::HslToRgb(redHsl);
-        VERIFY_ARE_EQUAL(255, red.R);
-        VERIFY_ARE_EQUAL(0, red.G);
-        VERIFY_ARE_EQUAL(0, red.B);
-
-        auto greenHsl = HSL{ 120.f, 100.f, 50.f };
-        auto green = ColorHelper::HslToRgb(greenHsl);
-        VERIFY_ARE_EQUAL(0, green.R);
-        VERIFY_ARE_EQUAL(255, green.G);
-        VERIFY_ARE_EQUAL(0, green.B);
-
-        auto blueHsl = HSL{ 240.f, 100.f, 50.f };
-        auto blue = ColorHelper::HslToRgb(blueHsl);
-        VERIFY_ARE_EQUAL(0, blue.R);
-        VERIFY_ARE_EQUAL(0, blue.G);
-        VERIFY_ARE_EQUAL(255, blue.B);
-
-        auto darkTurquoiseHsl = HSL{ 181.f, 100.f, 41.f };
-        auto darkTurquoise = ColorHelper::HslToRgb(darkTurquoiseHsl);
-        VERIFY_ARE_EQUAL(0, darkTurquoise.R);
-        VERIFY_ARE_EQUAL(206, darkTurquoise.G);
-        VERIFY_ARE_EQUAL(209, darkTurquoise.B);
-
-        auto darkVioletHsl = HSL{ 282.f, 100.f, 41.4f };
-        auto darkViolet = ColorHelper::HslToRgb(darkVioletHsl);
-        VERIFY_ARE_EQUAL(148, darkViolet.R);
-        VERIFY_ARE_EQUAL(0, darkViolet.G);
-        VERIFY_ARE_EQUAL(211, darkViolet.B);
-
-        auto whiteHsl = HSL{ 360.f, 100.f, 100.f };
-        auto white = ColorHelper::HslToRgb(whiteHsl);
-        VERIFY_ARE_EQUAL(255, white.R);
-        VERIFY_ARE_EQUAL(255, white.G);
-        VERIFY_ARE_EQUAL(255, white.B);
-
-        auto blackHsl = HSL{ 0.f, 0.f, 0.f };
-        auto black = ColorHelper::HslToRgb(blackHsl);
-        VERIFY_ARE_EQUAL(0, black.R);
-        VERIFY_ARE_EQUAL(0, black.G);
-        VERIFY_ARE_EQUAL(0, black.B);
-    }
-
-    void ColorHelperTests::LuminanceTests()
-    {
-        auto darkTurquoiseLuminance = ColorHelper::GetLuminance(winrt::Windows::UI::Colors::DarkTurquoise());
-        VERIFY_ARE_EQUAL(48.75f, darkTurquoiseLuminance * 100);
-        auto darkVioletLuminance = ColorHelper::GetLuminance(winrt::Windows::UI::Colors::DarkViolet());
-        VERIFY_ARE_EQUAL(11.f, darkVioletLuminance * 100);
-        auto magentaLuminance = ColorHelper::GetLuminance(winrt::Windows::UI::Colors::Magenta());
-        VERIFY_ARE_EQUAL(28.48f, magentaLuminance * 100);
-    }
-}
diff --git a/src/cascadia/ut_app/TerminalApp.UnitTests.vcxproj b/src/cascadia/ut_app/TerminalApp.UnitTests.vcxproj
index 608bce64b6..1eba2400bb 100644
--- a/src/cascadia/ut_app/TerminalApp.UnitTests.vcxproj
+++ b/src/cascadia/ut_app/TerminalApp.UnitTests.vcxproj
@@ -21,17 +21,11 @@
 
   <!-- ========================= Cpp Files ======================== -->
   <ItemGroup>
-    <ClCompile Include="ColorHelperTests.cpp" />
-
     <ClCompile Include="JsonUtilsTests.cpp" />
     <ClCompile Include="FzfTests.cpp" />
-
     <ClCompile Include="precomp.cpp">
       <PrecompiledHeader>Create</PrecompiledHeader>
     </ClCompile>
-    <ClCompile Include="..\TerminalApp\ColorHelper.cpp">
-      <PrecompiledHeader>NotUsing</PrecompiledHeader>
-    </ClCompile>
   </ItemGroup>
 
   <!-- ========================= Project References ======================== -->
diff --git a/src/renderer/atlas/AtlasEngine.cpp b/src/renderer/atlas/AtlasEngine.cpp
index 6bebd719e8..af9a92f89a 100644
--- a/src/renderer/atlas/AtlasEngine.cpp
+++ b/src/renderer/atlas/AtlasEngine.cpp
@@ -322,7 +322,7 @@ CATCH_RETURN()
             auto misc = _api.s.write()->misc.write();
             misc->selectionColor = newSelectionColor;
             // Select a black or white foreground based on the perceptual lightness of the background.
-            misc->selectionForeground = ColorFix::GetLuminosity(newSelectionColor) < 0.5f ? 0xffffffff : 0xff000000;
+            misc->selectionForeground = ColorFix::GetLightness(newSelectionColor) < 0.5f ? 0xffffffff : 0xff000000;
 
             // We copied the selection colors into _p during StartPaint, which happened just before PrepareRenderInfo
             // This keeps their generations in sync.
diff --git a/src/types/ColorFix.cpp b/src/types/ColorFix.cpp
index 7648de2262..d5a5fd1cd5 100644
--- a/src/types/ColorFix.cpp
+++ b/src/types/ColorFix.cpp
@@ -209,7 +209,14 @@ COLORREF ColorFix::GetPerceivableColor(COLORREF color, COLORREF reference, float
     return linearToColorref(oklab::oklab_to_linear_srgb(colorOklab)) | (color & 0xff000000);
 }
 
-float ColorFix::GetLuminosity(COLORREF color) noexcept
+COLORREF ColorFix::AdjustLightness(COLORREF color, float delta) noexcept
+{
+    auto lab = oklab::linear_srgb_to_oklab(colorrefToLinear(color));
+    lab.l = saturate(lab.l + delta);
+    return linearToColorref(oklab::oklab_to_linear_srgb(lab)) | (color & 0xff000000);
+}
+
+float ColorFix::GetLightness(COLORREF color) noexcept
 {
     return oklab::linear_srgb_to_oklab(colorrefToLinear(color)).l;
 }
diff --git a/src/types/inc/ColorFix.hpp b/src/types/inc/ColorFix.hpp
index 24c4cf79f3..60a7338731 100644
--- a/src/types/inc/ColorFix.hpp
+++ b/src/types/inc/ColorFix.hpp
@@ -10,5 +10,6 @@
 namespace ColorFix
 {
     COLORREF GetPerceivableColor(COLORREF color, COLORREF reference, float minSquaredDistance) noexcept;
-    float GetLuminosity(COLORREF color) noexcept;
+    COLORREF AdjustLightness(COLORREF color, float delta) noexcept;
+    float GetLightness(COLORREF color) noexcept;
 }