Mind you, this is Louisiana and it is dang hot. I have an acquaintance who is building a metal building for a barbeque joint. That's what we call them, lol. It's pretty big. I dunno, maybe 40x80. The crew is here now and they're putting it up and fast. I am aghast that all the walls (including the one facing west) are black! The roof is maroon. I am no expert but I would NOT have chosen dark colors. If he is set on those colors, he could have done that with accent painting. I would made the building white or silver or some light color. Cooling a building is a chore around here. This crew is just going to erect the frame and attache the metal panels. So, it will be a building when they leave but just that. The owner will DIY everything else. I admire the fact that this guy can do a lot of things. Handyman, jack-of-all-trades stuff. But I also have noticed that IMO, he might not research his ideas, talk it over with knowledgeable people, as much as he should. This project is a significant undertaking and he appears to struggle financially. I assume he got a loan. I asked him how he will insulate. He said he's going to put another "wall" of sheet metal inside the outside shell and have a guy blow foam inside it. I think that expanding foam stuff. What do you think of a black west wall and a roof that is dark red (maroon)? The good news is that the building will have an awning shading most of the west wall. Whew! At least, that will help. But he is not planning to shade the entire wall. If you have ten feet on each side of the awning that is not shaded, I fear that black ten feet on each side is going to make his building hot. Of course, he will have to have air conditioning. It would be hard to survive here in a metal building without it, lol. I mean, if people are going to want to eat in his place and watch sports on tv. The metal looks like steel panels, I don't think it is aluminum. If that matters.
I'm not a fan of spray foam, closed or open cell, when wood is involved. Had to fix too many with rot, mold and mildew caused by condensation. If it's steel framing then closed cell foam sprayed on walls and roof panels could work. Fill the rest of the void will fiberglass. It's cheaper.
So the building is going to look like what he is serving. Should make it easy to find. Most Space buildings here are insulated with 12 or 18 inch batts of sealed insulation, tightly packed together. And the buildings are usually light blue or white/tan.
Around here they are putting plastic on the purlins then spray foam over it. the plastic keeps the foam off of the outer metal and creates and air gap for circulation.