Add a setting for the unfocused tabRow background color

src/cascadia/TerminalApp/TerminalPage.cpp

@@ -4101,24 +4101,27 @@ namespace winrt::TerminalApp::implementation
 
             TitlebarBrush(acrylicBrush);
         }
-        else if (theme.TabRow() && theme.TabRow().Background())
+        else if (theme.TabRow())
         {
-            const auto tabRowBg = theme.TabRow().Background();
-            const auto terminalBrush = [this]() -> Media::Brush {
-                if (const auto& control{ _GetActiveControl() })
-                {
-                    return control.BackgroundBrush();
-                }
-                else if (auto settingsTab = _GetFocusedTab().try_as<TerminalApp::SettingsTab>())
-                {
-                    return settingsTab.Content().try_as<Settings::Editor::MainPage>().BackgroundBrush();
-                }
-                return nullptr;
-            }();
+            if (const auto tabRowBg{ _activated ? theme.TabRow().Background() :
+                                                  theme.TabRow().UnfocusedBackground() })
+            {
+                const auto terminalBrush = [this]() -> Media::Brush {
+                    if (const auto& control{ _GetActiveControl() })
+                    {
+                        return control.BackgroundBrush();
+                    }
+                    else if (auto settingsTab = _GetFocusedTab().try_as<TerminalApp::SettingsTab>())
+                    {
+                        return settingsTab.Content().try_as<Settings::Editor::MainPage>().BackgroundBrush();
+                    }
+                    return nullptr;
+                }();
 
-            const auto themeBrush{ tabRowBg.Evaluate(res, terminalBrush, true) };
-            bgColor = ThemeColor::ColorFromBrush(themeBrush);
-            TitlebarBrush(themeBrush);
+                const auto themeBrush{ tabRowBg.Evaluate(res, terminalBrush, true) };
+                bgColor = ThemeColor::ColorFromBrush(themeBrush);
+                TitlebarBrush(themeBrush);
+            }
         }
         else
         {

src/cascadia/TerminalSettingsModel/MTSMSettings.h

@@ -124,8 +124,9 @@ Author(s):
     X(winrt::Windows::UI::Xaml::ElementTheme, RequestedTheme, "applicationTheme", winrt::Windows::UI::Xaml::ElementTheme::Default) \
     X(bool, UseMica, "useMica", false)
 
-#define MTSM_THEME_TABROW_SETTINGS(X) \
-    X(winrt::Microsoft::Terminal::Settings::Model::ThemeColor, Background, "background", nullptr)
+#define MTSM_THEME_TABROW_SETTINGS(X)                                                             \
+    X(winrt::Microsoft::Terminal::Settings::Model::ThemeColor, Background, "background", nullptr) \
+    X(winrt::Microsoft::Terminal::Settings::Model::ThemeColor, UnfocusedBackground, "unfocusedBackground", nullptr)
 
 #define MTSM_THEME_TAB_SETTINGS(X) \
     X(winrt::Microsoft::Terminal::Settings::Model::ThemeColor, Background, "background", nullptr)

src/cascadia/TerminalSettingsModel/Theme.cpp

@@ -104,6 +104,10 @@ winrt::WUX::Media::Brush ThemeColor::Evaluate(const winrt::WUX::ResourceDictiona
     {
     case ThemeColorType::Accent:
     {
+        // NOTE: There is no canonical way to get the unfocused ACCENT titlebar
+        // color in Windows. Edge uses it's own heuristic, and in Windows 11,
+        // much of this logic is rapidly changing. We're not gonna mess with
+        // that, since it seems there's no good way to reverse engineer that.
         til::color accentColor = forTitlebar ?
                                      _getAccentColorForTitlebar() :
                                      til::color{ winrt::unbox_value<winrt::Windows::UI::Color>(res.Lookup(accentColorKey)) };

src/cascadia/TerminalSettingsModel/Theme.idl

@@ -34,6 +34,7 @@ namespace Microsoft.Terminal.Settings.Model
 
     runtimeclass TabRowTheme {
         ThemeColor Background { get; };
+        ThemeColor UnfocusedBackground { get; };
     }
 
     runtimeclass TabTheme {