Check out my posts in this forum. I use Estes Ceramaquartz "Teak" sand. Its a nice tan/orange and my polys look awesome on it.
Hmm check the fins and tail and over body should be normal. Any visual abnormalities should be a cause of concern.
If colors are faded then its kind if difficult to check for a WC or CB check with the store of origin.Dr.B is an expert let see his input on this.