Science Fair Project Encyclopedia White is a color (more
accurately it contains all the colors of the spectrum and is
sometimes described as an achromatic color—black is the absence
of color) that has high brightness but zero hue. The impression
of white light can be created by mixing (via a process called
"additive mixing") appropriate intensities of the primary color
spectrum: red, green and blue, but it must be noted that the
illumination provided by this technique has significant
differences from that produced by incandescence (see below). In
painting, white can be created by reflecting ambient light from
a white pigment. White when mixed with black produces gray. To
art students, the use of white can present particular problems,
and there is at least one training course specialising in the
use of white in art. Until Newton's work became accepted, most
scientists believed that white was the fundamental color of
light; and that other colors were formed only by adding
something to light. Newton demonstrated