Really Really Green

DD3 had just finished her bath. As usual, it seemed like a war zone in the tub with all her bath toys, nesting cups and maybe the occasional pool floats in there. She was picking up all these toys and putting them back in her tub toy container.
Me: There's a green cup behind you. (pointing to a dark green cup)
DD3: (turns around and picks it up) That's not green!
(digs into the container for a light green cup) THIS is green!
Me: What color is the other one then?
DD3: (puts both cups side by side) This (light green) is green and this (dark green) is really really green!