Normal Limbs only come in One Specific Color and you can not change its color.
Hypercamo Limbs are just like Normal Limbs but you can change and customize their color.

Hypercamo Experimental Limbs look more realistic, they no longer have bot-like features, and you can  change and customize their color. (If you have seen or used Seamless Parts Mod, They look just like Seamless Parts but a little worse visually)

All of the Bot Parts randomly appear in the Shop. It depends on your luck.