Once you close the Registry, you can now open Start menu or Action Center, and you'll notice that they are retaining its dark color.
On the right side, double-click the ColorPrevalence key and check the value to 2. HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Themes\Personalize Turn on the Show color on Start, taskbar, and action center toggle switch. Open the Start Menu, right click at any empty space and go to Personalize.
It's recommended to make a full backup of your computer before proceeding. Important: This is a friendly reminder to let you know that editing the registry is risky, and it can cause irreversible damage to your installation if you don't do it correctly. How to change taskbar color, while keeping Start and Action Center dark