question: can I recolor a pet after I upload a custom image overlay?

yep! i uploaded pinafore's custom overlay when she was a cream devonti, and later changed her to a nostalgic devonti, and she kept the overlay.

Thanks!

I think the only exception to this is if it makes it look like you have a pet that you don't have. For example, your overlay shows a glade devonti with a few modifications, but you have a cream devonti - or not even a devonti: a cream qrykee. As long as it's not being deceptive like that or trying to cheat the system, you should be fine.