"My" house is about half finished in construction. The basic structure is poured concrete with two floors. The downstairs floor, where I sleep, has been tiled but the upstairs has not. Nothing has been painted either inside our out. The plan is to paint the outside peach, the downstairs yellow and the upstairs a combination of blue and yellow.
When the sun gets to the western sky after noon it shines on the west wall of the house. Being dark, bare concrete the wall absorbs the sun's heat. If you put your hand to the wall it feels beyond warm, almost hot, to the touch. This adds a significant amount of heat to the house. When the exterior is painted I think the house will be cooler.