It's an illusion, the iris cannot change the shape of its aperture. Come on. You happened to inspect your eye while under the influence of a drug that effects pupil size regulation, and it is hard to discern the difference between the opening and dark irregular coloration along the inside of your pupil.
Sure it's cool, but not some crazy physical effect of DMT. Have you ever seen how David Bowie (RIP,
) has different colored eyes? He really doesn't (didn't), he was hit in the eye with a stick by his brother when he was a child, effectively permanently dilating it. The coloration appears different because you can only see the rim of one.
Eyes are beautiful, amazing, cool structures, highly evolved and specialized in function. They aren't just going to go all wonky like that. I've had similar observations on drugs though, one on ecstacy, I thought my pupils were vastly different sizes but i was just really really high and hallucinating.
Sine experientia nihil sufficienter sciri potest -Roger Bacon
*γνῶθι σεαυτόν*