Deuce, I disagree. I think bristle worms are and aren't reef safe. I'm sure if I was to lift my toadstool right now out of the substrate, he would have ten or more bristle worms screwed halfway into his base. one has just recently found a spot in the live rock when she seems to be bothering my bubble-tip anemone, and the anemone is closing and opening irrationally ever since then. and not one of these creatures are dying! anyway, bristle worms suck in my book. and if I could do it all over again and could not introduce any I would certainly do so... oh and as far as the color goes, I HAVE SEEN BROWN bristle worms in my own tank, I think it depends on what they've been eating.