I was just researching this. They are essentially different color theories. Newton came up with the red, green and yellow theory and no that's not a typo..it's green apparently. And Goethe came up with yellow, magenta and cyan as primaries. One (newton) is an additive method; the other is subtractive. Personally, I enjoy the tones of Goethe's theory. Cmyk is a delicious color wheel lol.
