What color is the presence of light?

There are many answers to the question you ask, this site explains how and why:

Color perception is also affected by the environment in which the color is seen. Daylight is rich in bluish tones because of the presence of ultraviolet radiation. Incandescent light and candle light are rich in yellow tones. The perception of any color requires the presence of light.

Our perception of color changes as the light source is changed or when the surface that reflects the light is stained or coated with a pigment.

What we commonly think of as color refers to the chromatic colors. These colors relate to the spectrum that can be seen in a rainbow. The neutral colors of black, white and grays are not part of these colors and are referred to as achromatic colors

* http://www.generalcolor.com/colorprin.html.