This lil guy was completely black when I picked him up from my LFS. But for some reason, Dats love my tank hence this pleasant surprise...(Please disregard the water stains on my tank glass)
And for your enjoyment (hopefully), here are some older tenants from my tank...
I know...I should've taken a before shot. It actually started stabilizing while I was floating it. At first glance, I thought it was going to be an ST. But I'll gladly settle for a PMST.
Re: why they stabilized so well...I'm not sure what the LFS's temperature was but mine is like 84. Also at the LFS, there was black sand and they were definitely blending in with the black sand. But to answer your question definitively...I have no clue. I just took a chance and lucked out.