Can pill color affect results

[Trippin']

I recently tested a pill and the reaction was to a yellow/orange color almost right away. A couple of people I know did one and felt absolutly nothing. He should have at least been wired. The pill was yellow and I was wondering if the color of the pill could affect the result of the test if there are no drugs present?

 

[aj]

Here we go again;
NOT to purple, NOT an Ecstasy like substance -> mdma/mdea/mda
Any other color, it could be anything really.
aj