The visual response to the wavelengths of light, identified as red, blue, green, etc. Color: primary and secondary colors; warm, cool, and neutral colors, color value; hue; and intensity. Color depends on light because it is made of light. There must be light for us to see color. A red shirt will not look red in the dark, where there is no light. The whiter the light, the more true the colors will be. A yellow light on a full color painting will change the appearance of all the colors.