The dark mode setting is reset upon restarting the game. Just clicking "save and exit world" and re-entering doesn't do this, it only happens when the game is completely restarted. Like my other opened issue, this is on 1.19 and the ATM8 modpack.

This seems to be an issue with 1.1.1. Reverting to 1.1.0 fixes the problem.

This problem seems to have returned in 1.19.2-1.1.3. I updated and on loading the client, the GUI was back to normal. I changed it to the dark mode I prefer, restarted the client and it was back to normal again.

FYI, Forge 43.2.14