^ Nah. The HCl makes the solution bubble/fizz, it has no color change on it's own.
Mecke reactions will turn green over time, I believe the mandelin will too. Haven't heard so for the marquis, but it wouldn't surprise me if it was possible. Typically adulterants will present themselves BEFORE the initial color change, it turning so long afterwards would point to some type of oxidization to me.
If you're really worried, send it into EcstasyData