What entheogenetor said.
Only one person I know of did a blind test and could not tell the difference.
Even very small amount of impurities can affect dmt crystallization and color. In fact, even the same batch of DMT can crystallize in different forms depending on crystallization method, since DMT is polymorphic. Pure DMT can also be seen as an oil. While the substance itself wouldn`t change in terms of qualitative effects depending on crystallization form, it could affect boiling point and therefore rate of ingestion which has an effect on trip strenght.
Regarding the content of the dmt extractions, most of the tests we`ve done so far on red vs yellow vs white dmt have shown very small differences in alkaloid content, basically some minor peaks from beta carboline related substances. Whether in such amounts they can affect the trip it is still unknown, but if so, they`d have to be very powerful substances. My guess is that in the amounts found in typical extractions of mimosa diplopterys and psychotria, it would not be noticeable. The DMT experience itself is already so variable even when smoking the same batch, same dose, I´d speculate that people could not tell difference in a blind test between such different colored batches. But again, only once we do those tests we`d know. Some people claim to feel differences but only one has actually gone through with blind testing and could not differentiate.
One thing to note though, is that when talking about Acacia or Phalaris extractons, there is a greater alkaloid variability, so it´s harder to generalize. Acacia confusa can have up to 70% NMT which is qualitatively different than DMT according to those who tried it purified. So an extraction from Acacia confusa, whether that is an oil or in crystals, if it has that high NMT content, could be different subjectively. Or other Acacias or Phalaris that have different tryptamines or beta carbolines. I never tried NMT or Acacia nor Phalaris extracts myself so I can´t say from experience.