Scientific Animation Optics: CMYK subtractive colour mixing orthographic

SUBTRACTIVE COLOUR MIXING

Subtractive Colour Mixing using cyan, magenta, and yellow. This simulation shows three light filters used in subtractive colour mixing. Each filter allows through two primary colours and subtracts (filters the other one):

• CYAN subtracts RED passes BLUE & GREEN
• MAGENTA subtracts GREEN passes RED & BLUE
• YELLOW subtracts BLUE passes RED & GREEN

• CYAN + MAGENTA yields BLUE (cyan removes the red and magenta removes the green)
  RGB -R -G = B
• CYAN + YELLOW yields GREEN (cyan removes the red and yellow removes the blue)
  RGB -R -B = G
• YELLOW + MAGENTA yields RED (yellow removes the blue and magenta removes the green)
  RGB -B -G = R
• CYAN + YELLOW + MAGENTA yields BLACK (cyan removes red, yellow removes the blue, and magenta removes the green)
  RGB -R -B -G = 0

Yellow, magenta, and cyan inks overlap to create the subtractive secondary colours (red, green, and blue). Where all three inks overlap the result is black. This type of colour mixing (using pigments) is the basis for colour printing. However, they generally also use black ink (the K in CMYK) since it is more efficient than relying on the three basic inks. This is known as four colour printing.