Very few store ammo in air conditioned bunkers. Least of all the Army, it's ambient temp with ventilation and the packaging is all there is to keep humidity away. I would think a smaller reloader using pulled or bulk bullets could more easily do it but there's a budget to consider. A/C costs me $200 a month for the house in the summer, year round storage would easily add $1000 a year per 2,000 square feet. That's a tiny ammo bunker for the big loaders. Open the door for shipping and you see why auto garages don't bother. Freezer storage houses have all sorts of air lock and strip dooring to keep the cold air in.
If the bulk pack wasn't heat sealed in a bag with dessicant then those bullets would have been received from storage and shipping in that condition. Tumbling again before loading is time and money, too. Up to a point, it's just cosmetic - looks - image - eye candy - ie nothing that contributes or takes away from being effective in use.
Kinda like the clear coat coming off the hood of my car (errgh!) it has no effect driving it daily to work. Shoot them vs clean new and perform forensic or gelatin testing, I seriously doubt there will be any recordable difference.
Plenty of people carry loads like that for 6 months at a time concealed. Entirely why we suggest to rotate them, but its based more on the rounds that get constantly rechambered more than discoloration. I've seen hunting ammo do that in less than 8 hours in the field under some conditions.