The texture colors wont really show on an extremely dark skin such as stealth.  If you apply a texture with a lot of dark/light contrast in it (the texture itself) to Stealth a look closely, you will probably see that the texture is actually being applied but just isn't easy to see.  The coloring mostly won't show on a very dark skin, though it might make it a little darker or a little lighter by the pattern.

A dark skin would be hard to add texture to, I assume. I never do it, but I think it'd be hard to get a texture to show on a dark skin.