@AHeinlein Hi there, that does seem odd and could potentially be a bug that needs to be looked into. The color shouldn't be changing when switching a gallery section layout.
Can you try this on your end?
Switch the layout from Grid: Masonry to Grid: Simple
Change the Aspect Ratio to another option
Change the Columns count
Toggle on Captions (you can toggle it off after)
Nonetheless, this behavior is definitely strange.