Revert "Revert "[File Explorer Add-ons] Fix file preview pane flickering on f… (#27093)" (#27122)

This reverts commit 217f3f9ff3.

src/modules/previewpane/powerpreview/powerpreviewConstants.h

@@ -5,4 +5,10 @@ namespace powerpreviewConstants
 {
     // Name of the powertoy module.
     inline const std::wstring ModuleKey = L"File Explorer";
-}
+    
+    // Dark theme background color
+    const COLORREF DARK_THEME_COLOR = RGB(0x1e, 0x1e, 0x1e);
+
+    // Light theme background color
+    const COLORREF LIGHT_THEME_COLOR = RGB(0xff, 0xff, 0xff);
+}