fix: support window accent color in frameless windows

Co-authored-by: Shelley Vohr <shelley.vohr@gmail.com>
electron · codebytere · Jun 25, 2025 · Jun 24, 2025 · Jun 24, 2025 · Jun 24, 2025
commit aa895795aee0e06f6346851140643e45bb820ec8
diff --git a/shell/browser/native_window_views.cc b/shell/browser/native_window_views.cc
@@ -430,6 +430,8 @@ 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.

diff --git a/shell/browser/native_window_views.h b/shell/browser/native_window_views.h
@@ -209,6 +209,7 @@ class NativeWindowViews : public NativeWindow,
  void ResetWindowControls();
  void SetRoundedCorners(bool rounded);
  void SetForwardMouseMessages(bool forward);
+  void UpdateWindowAccentColor();
  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
@@ -28,6 +28,53 @@ namespace electron {

 namespace {

+void SetWindowBorderAndCaptionColor(HWND hwnd, COLORREF color) {
+  if (base::win::GetVersion() < base::win::Version::WIN11)
+    return;
+
+  HRESULT result =
+      DwmSetWindowAttribute(hwnd, DWMWA_CAPTION_COLOR, &color, sizeof(color));
+
+  if (FAILED(result))
+    LOG(WARNING) << "Failed to set caption color";
+
+  result =
+      DwmSetWindowAttribute(hwnd, DWMWA_BORDER_COLOR, &color, sizeof(color));
+
+  if (FAILED(result))
+    LOG(WARNING) << "Failed to set border color";
+}
+
+DWORD GetAccentColor() {
+  DWORD accent_color = 0;
+  DWORD color_size = sizeof(accent_color);
+
+  HKEY key;
+  if (RegOpenKeyEx(HKEY_CURRENT_USER, L"SOFTWARE\\Microsoft\\Windows\\DWM", 0,
+                   KEY_READ, &key) == ERROR_SUCCESS) {
+    RegQueryValueEx(key, L"AccentColor", NULL, NULL, (LPBYTE)&accent_color,
+                    &color_size);
+    RegCloseKey(key);
+  }
+
+  return accent_color;
+}
+
+bool IsAccentColorOnTitleBarsEnabled() {
+  DWORD enabled = 0;
+  DWORD size = sizeof(enabled);
+
+  HKEY key;
+  if (RegOpenKeyEx(HKEY_CURRENT_USER, L"SOFTWARE\\Microsoft\\Windows\\DWM", 0,
+                   KEY_READ, &key) == ERROR_SUCCESS) {
+    RegQueryValueEx(key, L"ColorPrevalence", NULL, NULL, (LPBYTE)&enabled,
+                    &size);
+    RegCloseKey(key);
+  }
+
+  return enabled != 0;
+}
+
 // Convert Win32 WM_QUERYENDSESSIONS to strings.
 const std::vector<std::string> EndSessionToStringVec(LPARAM end_session_id) {
  std::vector<std::string> params;
@@ -450,6 +497,19 @@ bool NativeWindowViews::PreHandleMSG(UINT message,
      }
      return false;
    }
+    case WM_DWMCOLORIZATIONCOLORCHANGED: {
+      UpdateWindowAccentColor();
+      return false;
+    }
+    case WM_SETTINGCHANGE: {
+      if (l_param) {
+        const wchar_t* setting_name = reinterpret_cast<const wchar_t*>(l_param);
+        std::wstring setting_str(setting_name);
+        if (setting_str == L"ImmersiveColorSet")
+          UpdateWindowAccentColor();
+      }
+      return false;
+    }
    default: {
      return false;
    }
@@ -509,6 +569,21 @@ void NativeWindowViews::HandleSizeEvent(WPARAM w_param, LPARAM l_param) {
  }
 }

+void NativeWindowViews::UpdateWindowAccentColor() {
+  if (base::win::GetVersion() < base::win::Version::WIN11)
+    return;
+
+  // Chromium correctly updates accent color for framed windows.
+  if (has_frame() || !IsAccentColorOnTitleBarsEnabled())
+    return;
+
+  DWORD accent_color = GetAccentColor();
+  COLORREF border_color = RGB(GetRValue(accent_color), GetGValue(accent_color),
+                              GetBValue(accent_color));
+
+  SetWindowBorderAndCaptionColor(GetAcceleratedWidget(), border_color);
+}
+
 void NativeWindowViews::ResetWindowControls() {
  // If a given window was minimized and has since been
  // unminimized (restored/maximized), ensure the WCO buttons