How does brown DMT compare to white or yellow? I had 500mg of brown. We smoked it with my friend and never made full breakthrough. At best I got some good visuals from 80mg. Smoked from bong with layer of bud beneath and on top. If I'll ever get DMt or 5-MeO-DMT, I'll make "the machine".
Impossible to say, the brown / yellow / red color that DMT can have are impurities that may be active or inactive. For example if they are plant oils, the product will be less potent by weight and the resulting smoke may very well be harsher to inhale.
On the other hand if they are unidentified alkaloids found in the so-called 'jungle spice' the product could be more intense even than pure synthetic DMT and the subjective quality of the trip can be different as well. Some say deeper, darker and heavier. Indeed the strongest I think I ever had was red DMT, better than synthetic it seems... although I have no way of quantifying how much I was able to inhale effectively of either product.
Also note that white(ish) DMT may not be pure either: there are possible impurities that add no color.
So, considering the general rule: you cannot qualify a drug judging by color. But at the same time there may be some correlation: for example I'd say that if the color is positively red there is more of a chance there are jungle spice alkaloids in there while brown or yellow coloration are probably more likely to be inactives like plant matter crap or DMT N-oxide.
Also I'd say that if you produce white DMT there is a fair chance that it will be good quality because impurities
tend to be yellow or brown colored, generally speaking. And if your product is crystalline that is an extra indication of purity because the more pure a (re)X-ing mother liquor solution is, the bigger crystals can be formed. Also, the better the crystallization procedure (such as very slow cooling from a well saturated soln.), the bigger crystals. And the bigger the crystals, the more pure it is because impurities disrupt the crystal lattice.