Leather armor should be a thing, and hopefully dye-able (if possible/reasonable). It actually makes sense as an armor material.

This is something I've considered. I'm focusing on getting the foundations down right now, but I'm definitely considering adding in leather armor and dyeing.

I'm aware it is far in the future, just wanted to put it out there while I was thinking about it. :P

I spent the better part of the last two days giving this an honest shot, and I've hit a dead-end as far as dyeing goes. The Tinkers' system just wasn't built with that kind of feature in mind. I have the leather material itself all set, but without being able to properly implement dyeing I can hardly find a reason to include it. I'll definitely revisit this idea if I can ever figure out a way to do this, but until then this feature will have to be set aside.