Java Launcher doesn't support the dark mode in Windows 10. It's a little bit outstanding 🙂
MCL-16270
Launcher title bar does not respect system dark mode on Windows
Resolved
Works As Intended
0
Hi Andrey, if you want to change the title bar color you can do so by applying accent color to Title bars and window borders in Settings on Windows 10. Otherwise I am afraid Minecraft Launcher does not support 'dark mode' settings. If this is something you feel should be added, consider submitting a feedback request to aka.ms/mclauncher which we regularly review. If many others feel like you we will consider implementing it!