the U can pull it off. it just doesn't take the time or effort to do it. i.e. printing instructions for which color you must wear on all tickets before they go out. actually marketing it on radio, in print, on t.v., etc. the other thing i would venture a lot of these stadiums/teams do is keep the color scheme the exact same time after time and actually give a free t-shirt away that is the corresponding color on the day of the game. have people handing them out by section as you go to sit down. you get your correctly colored t-shirt for free and then for future color-out events you already have your correct color t-shirt on-hand and always comply by wearing it.
the overwhelming majority of gopher fans would participate and comply if the U of M truly made a concerted effort demanding that they do so. not announcing a gold-out game a few weeks before the game and hoping people follow along.
and being somewhat lazy in the approach and just doing a single color type of event (i.e. a gold out) throughout the entire stadium makes it easier in people's minds for them to be uncooperative d-bags and just not comply because it is easier to kind of get lost in the crowd of the whole stadium if you didn't cooperate. if you do color by section, a fan who doesn't comply is much more obvious in that "smaller" section/group of people and now has to rightfully take the flak and disdain from their fellow gopher fans in that section for not wearing maroon when they were supposed to. or not wearing gold when they were supposed to.
the U of M needs to do their color events by section and make a real effort to actually market it and make it easy for people to comply (i.e. hand out a free t-shirt once or twice a year (maroon one and then a gold one) and then do the color-out schemes and timing of them on a consistent and routine basis each season so it becomes the norm, commonplace and expected by returning fans and ticket holders.