What it does to a dark room
A pale floor changes a basement more than a pale ceiling does, because a floor is the largest continuous surface in the room and it is where most bounced light comes from. Glacier reflects a large share of what hits it, so pot lights that previously lit a grey floor and stopped now fill the room. In a below-grade space with one small window this is the single most effective thing you can do to the room short of adding glazing, and it is why we install more Glacier in basements than in any other space.
The garage problem, stated plainly
Hot-tire pickup is a bond failure, and a properly installed polyaspartic-topcoated floor does not suffer from it regardless of colour. That is not the issue with Glacier. The issue is tire transfer: a warm tire leaves a thin dark smear of tire polymer on the surface of any coating, and on a pale floor that smear is obvious. It wipes off with a stiff brush and a degreaser and it does no harm at all, but if the garage takes a car in and out every day, you will be looking at it and cleaning it. We tell every client this before they choose, because we would rather lose the upsell than install a floor somebody quietly regrets.
Where it is unbeatable
Showrooms, studios, display garages and any space where things are looked at rather than driven on. A pale floor makes whatever sits on it the subject, which is exactly what a retail floor is for, and the visible cleanliness is part of the message. In those rooms the maintenance that makes Glacier wrong for a daily-driver garage is already happening daily anyway.