Pale Tang just stress or problem?

[falconut]

My LFS has two Orange Lined Bristletooth Tangs (one's about 1" and the other is about 1-1/2" to 2"). The smaller one is darker with more vivid coloration and the largere one is more of a sand color with less vivid coloaration. Is this just stress or a sign of a problem? All opinions welcome.

 

[Sk8r]

It could be individual difference. But I'd worry a bit. I'd expect the larger to be dominant, ergo more vivid color.

 

[falconut]

They are in two different tanks. The smaller one has some rocks and things and the larger has just a few pipes. If it makes a difference.