Hey /toy/ I want to make a semi-realistic Sonic figure but I've never painted a toy before.

What kind of paint should I use to more or less stain the spikes on this figure to have a blueish tint? I just don't want to slather it with some ugly opaque blue normal paint, I'd like it to be translucent-ish. I'm also planning on painting an echidna figure red-ish. Any help you be greatly appreciated.