Behr exterior house paints are formulated to be slightly more flexible than their interior counterparts. This is because exterior paint needs to withstand temperature extremes. The paint on the south face of a home in the hot summer sun can get up to 130 degrees Fahrenheit. In the dead of winter the same painted surface can drop to -40 degrees Fahrenheit. Beyond the exterior paint itself being able to withstand these temperature extremes, the surface it is applied to expands with the heat and contracts with the cold. The amount of expansion and contraction varies from substrate to substrate. Then there is a number of challenges that humidity causes with exterior house paint. From the absorption of humidity in the air to moisture working its way from the interior to the exterior (especially in colder weather).
Even with all the exterior environmental variables that the Behr exterior house paint has been engineered to withstand, it is available in all the colors that Behr interior paint colors are offered in.