But there isn't a word for cyan and magenta, hence the need to define cyan in terms of RYB. cyan = blue + green green = blue + yellow cyan = blue + (blue + y

But there isn't a word for cyan and magenta, hence the need to define cyan in terms of RYB. cyan = blue + green green = blue + yellow cyan = blue + (blue + yellow) Well, technically: 2 parts cyan = 1 part blue + 1 part green 2 parts green = 1 part blue + 1 part yellow 2 parts cyan = 1 part blue + 1 part (1 part blue + 1 part yellow) i.e. 2 parts cyan = 1 part blue + 1/2 part blue + 1/2 part yellow i.e. 4 parts cyan = 3 parts blue + 1 part yellow But I think the real lesson here is that colour names based on additive colour mixing are silly.