From 31725b4a861feb2ddbd31016a46d18e5a305f7f0 Mon Sep 17 00:00:00 2001
From: Shelley Vohr <shelley.vohr@gmail.com>
Date: Thu, 17 Jul 2025 10:59:42 +0200
Subject: [PATCH] fix: window `accentColor` should adhere to native window
 behavior (#47740)

* fix: window accentColor should adhere to native window behavior

* fix: address review feedback

* chore: remove duplicate UpdateWindowAccentColor call in ctor
---
 shell/browser/native_window_views.cc     | 8 ++++++--
 shell/browser/native_window_views.h      | 2 +-
 shell/browser/native_window_views_win.cc | 8 ++++----
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/shell/browser/native_window_views.cc b/shell/browser/native_window_views.cc
index 00a9e8639b..ee1040d0d9 100644
--- a/shell/browser/native_window_views.cc
+++ b/shell/browser/native_window_views.cc
@@ -420,8 +420,6 @@ NativeWindowViews::NativeWindowViews(const gin_helper::Dictionary& options,
     last_window_state_ = ui::mojom::WindowShowState::kFullscreen;
   else
     last_window_state_ = ui::mojom::WindowShowState::kNormal;
-
-  UpdateWindowAccentColor();
 #endif
 
   // Listen to mouse events.
@@ -1732,6 +1730,12 @@ void NativeWindowViews::OnWidgetActivationChanged(views::Widget* changed_widget,
     NativeWindow::NotifyWindowBlur();
   }
 
+#if BUILDFLAG(IS_WIN)
+  // Update accent color based on activation state when no explicit color is
+  // set.
+  UpdateWindowAccentColor(active);
+#endif
+
   // Hide menu bar when window is blurred.
   if (!active && IsMenuBarAutoHide() && IsMenuBarVisible())
     SetMenuBarVisibility(false);
diff --git a/shell/browser/native_window_views.h b/shell/browser/native_window_views.h
index 87dbf4bb73..2872d77c32 100644
--- a/shell/browser/native_window_views.h
+++ b/shell/browser/native_window_views.h
@@ -222,7 +222,7 @@ class NativeWindowViews : public NativeWindow,
   void ResetWindowControls();
   void SetRoundedCorners(bool rounded);
   void SetForwardMouseMessages(bool forward);
-  void UpdateWindowAccentColor();
+  void UpdateWindowAccentColor(bool active);
   static LRESULT CALLBACK SubclassProc(HWND hwnd,
                                        UINT msg,
                                        WPARAM w_param,
diff --git a/shell/browser/native_window_views_win.cc b/shell/browser/native_window_views_win.cc
index 21fbdcfed8..7baa349bd9 100644
--- a/shell/browser/native_window_views_win.cc
+++ b/shell/browser/native_window_views_win.cc
@@ -499,7 +499,7 @@ bool NativeWindowViews::PreHandleMSG(UINT message,
       return false;
     }
     case WM_DWMCOLORIZATIONCOLORCHANGED: {
-      UpdateWindowAccentColor();
+      UpdateWindowAccentColor(IsActive());
       return false;
     }
     case WM_SETTINGCHANGE: {
@@ -507,7 +507,7 @@ bool NativeWindowViews::PreHandleMSG(UINT message,
         const wchar_t* setting_name = reinterpret_cast<const wchar_t*>(l_param);
         std::wstring setting_str(setting_name);
         if (setting_str == L"ImmersiveColorSet")
-          UpdateWindowAccentColor();
+          UpdateWindowAccentColor(IsActive());
       }
       return false;
     }
@@ -570,7 +570,7 @@ void NativeWindowViews::HandleSizeEvent(WPARAM w_param, LPARAM l_param) {
   }
 }
 
-void NativeWindowViews::UpdateWindowAccentColor() {
+void NativeWindowViews::UpdateWindowAccentColor(bool active) {
   if (base::win::GetVersion() < base::win::Version::WIN11)
     return;
 
@@ -589,7 +589,7 @@ void NativeWindowViews::UpdateWindowAccentColor() {
     should_apply_accent = std::get<bool>(accent_color_);
   } else if (std::holds_alternative<std::monostate>(accent_color_)) {
     // If no explicit color was set, default to the system accent color.
-    should_apply_accent = IsAccentColorOnTitleBarsEnabled();
+    should_apply_accent = IsAccentColorOnTitleBarsEnabled() && active;
   }
 
   // Use system accent color as fallback if no explicit color was set.