The degree to which a material will reflect incoming solar radiation
(all "light" from the sun, including but not limited to
infrared, visible and ultraviolet light) is governed by the material's
albedo, a measure of its solar reflectivity. Albedo is therefore
more than just reflectivity, since it measures reflectance of solar
radiation, not just reflectance of light in the visible spectrum.
Consequently, color in the visible spectrum is not always a true
indicator of albedo.
In general, however, materials that appear to be
light colored in the visible spectrum have high albedo and dark colored
material shave low albedo. The ability to reflect infrared light is of
great importance because infrared light is most responsible for heating.
Albedo is measured on a scale of 0.0 to 1.0, with 1.0 representing the
highest reflectance of solar radiation.More on What is Albedo ?