Hmm, my experience is that it isn't that hard to keep color on WC blue jeans but getting the offspring to color up is a challenge. I got my 1.2 blue jeans as adult wc in 1999 and the male has always been orange (still is) but the females are brilliant red. I'm reluctant to mention this but I've used VERY low doses of canthoxanthin to keep the color on when I can't feed meadow plankton (which also does the trick).
As for coloring up babies, I'm still working on it but may be gaining. I'm starting to think that getting the pigment set during development may be pretty important because it seems to be harder to color up dull frogs than to keep them bright. However, I've also had froglets that get pretty good color and then fade. I've been reluctant to do much with canthaxanthin on froglets because of the potential problems with hypervitaminosis, especially in a very small frog. But lately I've been leaving the froglets in the breedig viv with the parents much longer than normal. I mixed about a fingernail full of canthoxanthin with a 4 oz. jar of vitamin powder and have been dusting with that powder once a week to feed the adults. Since the juvie is getting the same diet, it also gets these low dose flies. The latest froglet is about half grown and yesterday I saw it next to a female and was pleased to see a bright crimson color just like the adult. It's too early to say whether the color will stay but this is the best one I've produced yet.
I'm also hoping to set up some red spider mite cultures to see if they help with the coloring. I know from experience that using meadow plankton as a staple really helps maintain color but it would be nice to find a few culturable insects that could do the same thing.