I would say try more layers of paint then. You'll get a richer color too.
Try using this kind of paint if you have the extra $. I adore Utrechts for normal painting, and you can get a set of 5 paints for like $20, and mix any other color you might need. I really really love their Gesso too. Its so nice.
/jealous
I just got into making little clay charms as well, and have even sold a few. I need to expand my items though, since I've only done a frog, some cupcakes, a Tail's Doll, and Hello Kitty. I think I might do a little octo, cause they're adorable.
But anyways, enough about me. Yours are AWESOME. Like, totally better than mine. But I just need a little practice, I guess. Keep making them, and maybe you can make a huge profit. :D
I like the little squid things ;3