True, Tren A can do without heat. But heating also is another sterilization precaution. BA/BB should do the trick, but why not heat it? It’s not difficult.

I have homebrewed hundreds (really, hundreds) of vials of Tren - probably thousands of milligrams - and both colors of your Tren look normal. As some mentioned earlier, it can be the heat. But it can also just be the slightest variant in the product that will tip it over to a brown instead of a gold. So, yes, absolutely, it can be both your heating process (not likely) or your product (possible). But it does not mean your product is sub-standard, or “not fresh.” (Seriously, that “not fresh” comment is bullshit.) I have brewed Tren A powder less than 24-hours after the powder process was complete, and still got deep gold/brown Tren.

Tren can be, slightly, more delicate than, say, something easy like Test when you are homebrewing. But, from your process you mention above, you aren’t putting it through anything tough. I brewed every single powder I ever made at between 180-200 for 20 minutes. Over six years - no complaints. I dosed slightly higher in the mix (only very slightly) to compensate for anything that might get lost/disrupted due to the hight heat. One thing heating does, remember, is force the powder into a suspension. Most AAS compounds are in suspension, not solution. So - sometimes - heat helps the suspension process and your gear won’t crash.

Is the brown Tren more painful to inject? It should’t be. Also, the potency shouldn’t change just because it’s brown instead of gold.