Help Instant dark brown

[nupharizar]

I bought single-use Marquis tests, and in one, I checked for MDMA, and in the other, for amphetamines. I'm sending the results in the picture below. Is it normal that with amphetamine, the color changed almost immediately to a very dark brown? I should add that I washed it with acetone beforehand.

At the top, amphetamine; at the bottom, MDMA

Photo