Comment by coffeeling

Cyan isn't between green and blue, at least not completely. If you take green and blue, you won't be able to represent a good chunk of cyan hues. It feels greenish and blueish, but is neither, and is broader than any combination of the two, which is partly why some bright cyan objects (like the bird eggs on Wikipedia) look kind of unnaturally intense. Those eggs are a bright, slightly blue-leaning cyan.