I think I found out how to do it in PhotoShop. Image > Mode > Indexed Color...
It actually says:
Colors:
I edited it to 16 and it doesn't glitch in BWSE 2.0 anymore (YES!) but, how do I compress the files now? I'm not used to Tinke, the files are different than what I am used to. I know I must use kiwi.ds, but what do I do?
EDIT: Yes, it works! I found out how to do it. Thanks so much for your help!
Do you, by any chance, know how to make the rival sprites not move, by the way? ^^"
Also, the only sprites I'm still having trouble with are the mugshots, I made SURE they indeed ARE 16 colors, but they look all negative In-Game (Cheren & Bianca) and the eyes and hair are see through (Hilbert, I used a Trainer Red sprite)
Any chance you have a BWME 2.0 as well? Would save my life!
Then I would just need to learn how to insert music properly and I continue my project!