Just doing some tweaks to some of the dalish armours and I was wondering if anyone has figured out which channel on the tint map is linked to which material slot in the crafting menu. Green seems to be linked to the main material slot from what I can tell but I'm not sure about the others.
It's going to be different depending on what mesh you're working on.
For example: Dalish scout armor

Each channel of a tint is a mask. It does whatever Bioware wants it to do, and there doesn't seem to be a universal convention as far as I can tell.
Outside of finding a way to see what they do in the actual code, you can infer via what gets put where by looking at the crafting table.
For the casual versions you wear around skyhold, you're never going to change the actual materials of the outfit with a tint map. All you're doing is moving around what gets put where.