Hi Mike. We have used the Sherwin Williams 2 part concrete paint with good results on one hangar at GTU and two home shops. Its a little pricey and requires 2 gal min purchase. We used the white and also mixed white with grey for a light grey result. Follow instructions and it applies easily and quickly with rollers. Widely available.
Only downside is some long term discoloring in direct sunlight. Big upside is no concrete dust, easy to clean, impervious to most spills, can be cleaned and rebuffed after several years if needed.
Good Luck,
Deene.