Red, green and blue are the primary colors of light. All other colors can be produced by mixing two or more of these colors in varying amounts and intensities. Remember: COLOR is a mental perception, based upon stimulation by light of particular wavelengths or frequencies. If there is no brain, there is no color, only light waves. What color do you think your blood is, while it is still inside your body where no light falls upon it?

Red + blue +green ( in equal amounts) = white.

Colors opposite (180 degrees) each other are complimentary. When combined, they produce white. Note the RGB color boxes. Color combinations that produce a full RGB box are complimentary.

Cyan, yellow and magenta are the secondary colors of light. Any secondary color mixed with it’s compliment produces white light. Note that our brain has the tendency to percieve an average of the wavelengths striking our eye. When equal amounts of both red and green enter our eye, the brain percieves yellow. The eye is more sensitive to reds and greens, and less sensitive to blues. This is why darker blue colors are more difficult for us to differentiate than darker shades of red. Something entirely different happens with our perception of violet. Violet color can be produced by mixing red and blue in the right proportions, but our brain still perceives violet at the shorter wavelength end of the spectrum when no red light at all is present.

In the RGB boxes, the colored bands are the colors which, when present in equal amounts, produce the labeled color while the “blank” bands are the light colors absorbed by an object that reflects the labeled color. For example: cyan is produced when equal amounts of blue and green are mixed, but a cyan object absrobs red. Also, a red transparent filter absorbs the “blank” band colors green and blue, permitting only red wavelengths to pass.

TRENDS APPARENT WITH THIS MODEL

Mixing colors of light additively.

• In this wheel model, any two successive primary colors of light, when mixed additively and equally, produce the secondary color which lies between them. Any two successive secondary colors, when mixed additively and equally, produce white. Any two colors that are 180 degrees opposite each other, when mixed additively, will produce white.
  
  
• Mixing all three primary or secondary colors equally produces white.
  
  

Mathematical representations of color addition:

• Red + Green = Yellow
  Green + Blue = Cyan
  Red + Blue = Magenta
  Red + Green + Blue = White
  
  
• Red + Cyan = Red + Green + Blue = White
  Green + Magenta = Green + Red + Blue = White
  Blue + Yellow = Blue + Red + Green = White
  
  
  

Mixing colors of light subtractively.

• A red filter transmits only red, subtracting out green and blue. Filters of the colors on either side of red both pass red as well. Thus, if a yellow filter is stacked on top of a red one, and white light is aimed at the stack, red can still get through. The same result happens when red and magenta filters are stacked. Similar trends can be seen with any primary color and it’s two neighboring secondaries.
  
  
• However, if any primary light filter is combined with a filter of it’s complimentary secondary color, the subtractive process yields black, since all colors are effectively blocked.
  
  
• Filters of any two consecutive secondary colors when mixed in this subtractive fasion, will yield the primary color that falls between them on the wheel.
  
  

Mathematical representations of color subtraction:

• White - Red = Green + Blue = Cyan
  White - Green = Red + Blue = Magenta
  White - Blue = Red + Green = Yellow
  
  
• White - Yellow = White - (Red + Green) = Blue
  White - Cyan = White - (Green + Blue) = Red
  White - Magenta = White - (Red + Blue) = Green
  
  

Several other patterns may be detected by the discerning eye here. Give it a shot and see what relationships you can come up with!

Check out this page to mix light in an ADDITIVE form, as though you were shining light of the various primary and secondary colors on a screen. A browser that can handle JAVA is necessary. Most "4.0" or later browsers can do this.

AND then check this page to see what happens in a SUBTRACTIVE condition, as though light is FILTERED through prisms of each of the colors.

Download your own copy of our color wheel activity page (in case you mess up the one you got in class!)