Chameleon ability is one of the more easily accomplished tasks. All one need do is cover the epidermis with chromatophores.
There are prices to be paid for such abilities, however. Sure, it would be cool to have tattoos that would be under your conscious control, even being animated if you wish, but you would have to "cloth" yourself in tattoos. Think of body painting. It is remarkably deceiving to the eye, but under the paint is only skin!
This also requires considerable brain-power and associated control networks. These would have to be supplemented in the chameleon-enabled population.
Since it works best to conceal oneself flat against a wall, it would be almost useless if the chameleon strayed too far from the surface it was imitating. Walking among a crowd unseen requires a different technology.
I'm back. :-)
True.
Chameleoid ability would be useful in wooded areas and such.
Light bending or dimensional phase shifting would be best used elsewhere.