Can i get tips on choosing colors for characters? (Mainly colors)

I usually make ocs and i realize i do struggle with picking colors for their outfits and such. I typically go based on what i think looks good and look at it with grayscale after to make sure it doesnt really blend in. But somehow it doesnt look that good to me anyway. I'd just like some tips/advice please!

(I dont have any examples on me of my art, i dont think its rlly needed for what im looking for since its general advice hh