Each receptor is sensitive to about one-third of the visible spectrum. These are red light, green light, and blue light. The color the eyes see in an object depends on how much red, green and blue light is reflected to the eye. Black is perceived when no light is reflected to the eye. When red, green, and blue lights are reflected to the eye in equal amounts, then white is perceived.
Many factors can affect our perception of color.
A person who looks at color for a long period of time is going to experience retinal fatigue and the colors are not going to be perceived accurately any longer. We need a standard specification system to know exactly what the color is. The conditions in which color is viewed greatly affect the perception of color. For accurate viewing the light source and environment must be standardized. People in the graphic arts industry, for example, avoid fluorescent and tungsten lighting, use a standard light source, and proof against a neutral gray surface.