Green definitely, but if you are going to have a small SPS reef watch out. Make sure your corals are big or else breeding clown gobies will probably kill frags. These aren't meant for the fruit stand frag collector, but more for someone with very large established colonies of SPS or the coral will suffer.
FWIW, they can be bred without coral, if you really are interested in breeding this species and it can be done in a very small tank, that maybe you could tie into your SPS tank for stability if you don't want to risk the corals.
Good luck!