ooohhh yes, that can be difficult at the start!
It's worth trying to learn a bit of colour theory then! I've recently looked at my old stuff and was cringing so much at my colour choices. hahaha But I hadn't properly realised until that moment how much the colour theory courses I had at my animation school had improved my eye and instinctive choice of colours! I'm still no expert and mainly play it by ear (errr eye? lol ) but it's super worth looking into the theory of what colours go together and values and contrast and colour palettes and all that good stuff ;) <3
and thank you Kothy!! <3 <3 <3