Problem is caused when you upload an aia. You have to delete projectColors by editing aia’s projectsettings. Devs are informed about this bug (since Apr 2022, well, they are a bit slooooow…)
Temporarily solution for all components How to fix Kodular’s colors errors - Latest release Fenix 1.5.4 - YouTube
(taken from here Background color options are not working in this version - #8 by dora_paz)
Taifun