red, green, blue
The human eye can distinguish only red, green, and blue light. These three colors are called the primary colors of light. All other colors of light can be created by combining the primary colors. Look at the Venn diagram below . Red and green light combine to form yellow light. Red and blue light combine to form magenta light, and blue and green light combine to form cyan light. Yellow, magenta, and cyan are called the secondary colors of light. Look at the center of the diagram, where all three primary colors of light combine. The result is white light. You can explore the colors of visible light and how they combine at this URL: http://www. phy. ntnu. edu. tw/oldjava/color/color_e. html.