You know, our short-lived "Indian Summer"--highs in the 60's to 70's in the Midwest this week--will be gone in a few days. I suggest you go with white latex primer, white latex paint. Go back next spring and change the color then, if you want to.
I'm finishing painting my enclosed, unheated front porch this week. DD and I are 1/2 done, and the storm window and the front house door will be done by Wednesday. I'm R E A L L Y pushing it painting THIS LATE. I'm also painting two horse training poles with oil-based paint. I'm making them from two clothesline poles that have damage on the top, so they can't be used for that anymore. I started Friday with white oil-based. It took until late Saturday afternoon with temps in the 70's, for them to dry, 1st coat. Second coat will be the black stripes. They probably won't be ready for any use for another week. The quality of THIS job is not important, but I'm recycling my materials.
Consider this: the more light you give your chickens, the more egg-laying they will do. Sooo, how about white or pastel shades for the inside of the coop? Good luck!