I think blue ridge is the exception. I'll have to look around for the reference. But like pipe organ coral's skelton is red, it does not fade to white when it dies or even if it is left out in the sun. I believe blue ridge is blue even when it dies. This comes from some research I did when I first setup my tank and put fake corals in there :blush :sick . These were the 2 that were not dyed from dead coral