I drink RC cola
in my GM truck
down BY the river

thats a simple anagram thingy I learned in my graphics/printing classes about filters and colors. This is also knows and "subtractive color theory".
red filters magenta and yellow, thus prints Cyan
Green filters yellow and red, thus prints Magenta
Blue filters magenta and cyan, thus prints yellow.

I dont do any color photography printing, but that is at least a simple explanation of color theory.