How do I set a custom default accent color during deployment of Windows 10?
Predefined colors are deprecated. Use a custom hex ARGB color value preceeding with 0x. E.g.: 0xff0078d7 (default blue). Or you may want to use 'Automatic'. More infomation: https://docs.microsoft.com/en-gb/windows-hardware/customize/desktop/unattend/microsoft-windows-shell-setup-themes-windowcolor