i also noticed but didn't think much of it at first... there seems to be a bit of yellow and orange at first. and even when it turns brown there is a slight yellow outline that sticks around... i don't really know much about the "bath salt" chems other than they turn yellow, but it looks possible that it might have a small bit of something other than amphetamine in their.
i didn't say anything at first because i really don't understand why someone would cut what looks like pretty good speed with some sort of bath salt (or what ever you want to call the RC stims that turn yellow with marquis). i have only done speed, meth, and coke as far as stims go and i don't know how the class of drugs that react yellow feel... but maybe its to give that feeling etarded is talking about to more easily trick you as that its MDMA from the experience?
but yea for what its worth it looks like its is cut very lightly, maybe 10%, with something else judging from the multiple colors. to me it doesn't really just look like different shades of brown.