Even without a skin, you can tweak PotPlayer:
By pairing PotPlayer's unmatched playback capabilities with a sleek, Windows 11-optimized skin, you get the absolute best of both worlds: a media player that plays everything flawlessly while looking like a native, modern Windows application. potplayer windows 11 skin
Navigate to and select your newly added skin from the list. Even without a skin, you can tweak PotPlayer: