Big chance its not WSLg issue, but maybe somebody will able to tell where to look: Most apps respect current GTK_THEME and use **window decorations** from it. But some, most important JetBrains IDEs won't and for example xcalc. What part of this magic system is responsible to choose what window decoration theme to use? Can i force it to use some dark theme by default? <img width="1038" alt="win-decorations" src="https://user-images.githubusercontent.com/833192/115714487-d5ea2c80-a37f-11eb-847e-0525e99eaa35.png">