The birdnest I kept never colored up either. I had it all the time up on a frag rack in the main tank but once I have my frag tank up and running next week I think I will blast it under MH like Jeremy was advising and see if I could get it to turn pink.
Otherwise I guess it will be called a brown birdnest ;D
Alright had some issue with the favia, none of my diamond wheels actually had any diamond dust on the edges, so it wasn't working for cutting. I hit it with a screwdrivers and I got a couple polyps off that are kind of broken. I'll see what they do between now and next month.