whether it is a color or not is debated among scientists. black has some kind of a similar standing as white is.
some say black is the absence of any color, therefore it is not a color.
some say white is the absence of pigments and molecular coloring agents, therefore not a color.
in general, white is considered to be the reflection of all colors of the visible light spectrum to the eyes. so, white is a color.
but still debated...