Gainsborough’s ‘Blue Boy’ was painted with just three pigments – he was not happy... Courtesy of the Huntington Library, Art Collections, and Botanical Gardens, San Marino, California Light - Additive Mixing RGB Primaries Paint - Subtractive Mixing CMY Primaries The Primaries for Light (RGB) and Paint (CMY) are the complements of each other: To put the record as straight as possible: There is only two sets of correct primary colours, one for additive and one for subtractive mixing, see 1. above.  Secondary colours  for paint are: red, green and blue. The Truth about Colour