CMYK

From ColorWiki

The four colors commonly used in process color printing. Black is added to CMY to enhance the density of dark areas and solve gray balance problems encountered when trying to make neutral grays with CMY alone.

The letters stand for: C: Cyan M: Magenta Y: Yellow K: Key Color (which is usually black)

See Also

• Subtractive Primaries
  
• Process color
  
• The Color Key article