Can speak about the IPs but vendors for Polymer 80 has those colors if you want to build your own. With careful shopping for deals can cost about the same as a new one
I got the bronze from 2A and get compliments on it all the time. I love it. (it's not for sale.) Ive seen gray in 2A regular, and they used to have magpul FDE regular. I'd give mark and tom a call. (but I'm a fanboy, they're nice to my dog.)