Painting Walls

[Opus007]

Will painting my walls flat black make the room hotter in the summer time.There is only one window with black out curtains that gets sunlight most of the day and the outside walls , 2 of them get direct sunlight most of the day.Thanks.

[Burke Strickland]

Maybe the room would get hotter if the walls were painted flat black on the outside of the house and there were little or no insulation in the walls, but painting them black INSIDE the house (even if they are "outside" walls) should have no effect on the room's ambient air temperature, especially since the room's one window is blocked with blackout curtains.