There were dead larva (e?)in the cells with brown spots. They looked like they‘d been uncapped. Aside from these few spots the rest of the frames looked very good (as far as I could tell anyway).
Probably drone brood that didn’t make it out would be my guess for those 4 cells, as for the brown spot, it might just be the color of the wax.I dont think it got chilled? I had capped swarm cells last week and did an unplanned split. This frame is from one of the newly split hives, 7 days after the split. I am pretty sure there were a lot of bees in there. It did get a little chilly (50’s) for 2 days but I am thinking there were enough bees to cover them. I could be wrong. After closing everything up I realized it would have made sense to open those 4 drones and see how they look. The spots definitley don‘t move.