Out of curiosity: when you go full throttle on red yellow, dark <-> light goes from red to orange to yellow. Is that really as it is meant to be? I'd (intuitive

Out of curiosity: when you go full throttle on red yellow, dark <-> light goes from red to orange to yellow. Is that really as it is meant to be? I'd (intuitively) expect to be able to go from orange to brown by adjusting the dark/light dimension.