I can add a little to the licensing discussion, as I just recently co-branded with many of the southeast's D1 schools, Tech being one of them. I'm a general manager of a golf course here in GA, and I recently co-branded (my course logo on the front, school on the right side) with Tech, Clemson, Alabama, South Carolina and Auburn. Working through New Era, my hat manufacturer, we have to design the hat, down to the base hat material, color, logo placement, size, etc. Each design is then submitted to the school directly (I do not know who/what dept at each school does this, New Era assisted with the submissions) for approval. Each school can reject the item/logo use on any number of things...material color, logo size, placement, thread color, etc. Now, New Era obviously does a lot of merchandise for most all schools, so they can (and do) give advice along the way for what they've seen work in the past, but each design has to still be individually approved. Auburn rejected our first attempt but then allowed it, and UGA would not give us permission to use their logo, stating something to the effect of they do not license to golf courses at this time (I forget the exact wording of the response).
Once a design is approved, I can't change anything about that design for follow-up/fill-in orders. Material, hat base color, even my own course logo or thread colors, or else it has to go back for approval again. So at least in my own direct experience, the school has a lot (actually the final say) in what merchandise will look like, and what colors are used. FYI, my "GT" on our caps is gold thread, not cheddar yellow.