"Our modern understanding of light and color begins with Sir Isaac Newton and a series of experiments that he published in 1672. He was the first to understand the rainbow — he refracted white light with a prism, resolving it into its component colors: red, orange, yellow, green, blue and violet.
Artists were fascinated by Newton’s clear demonstration that light alone was responsible for color. His most useful idea for artists was his conceptual arrangement of colors around the circumference of a circle, which allowed the painters’ primaries (red, yellow, blue) to be arranged opposite their complementary colors (e.g. red opposite green), as a way of denoting that each complementary would enhance the other’s effect through optical contrast."
Still today Newton's color system is used in fine arts.
But coming back to light:
One of the contemporary artists who is using light as a medium for art is the American Stephen Knapp.
His huge installations are made only of coated glass and light. The visible color on walls is reflected and affected by the angle of the glass to the light source - usually a halogen light. The glass reflects in two directions and the colors shoot around, overlap and create new color mixes.
More about Stephen Knapp