Regal Tang question
 

I finally found some regal tangs at a lfs which are around 2". The blue color on them seems a little pale. Does the color brighten up as they grow or is this just a poorer quality of fish?

If the colour was pale the fish was stressed out and best left at the store. If you are going to buy one look for a bold and colourful one.

The fish are in poor condition avoid buying them. Wait until a perfect tang arrives and ask the LFS to feed the fish. It should feed aggressively. It should be colourful, active, clear eyes, no bloches, or torn fins. A fish just as interested in you as you are in her.
Than buy her. This applies to all fish purchases.

I agree with what Naesco said but don't give up hope on the tangs you saw at the store. If they were just brought in they may still be stressed from shipping. Observe them over the coming days and see if they recover.