Your chances for green eggs are likely remote, Olive green very remote.
My genetics is sketchy but when I was wondering if my EE mixes would have green eggs, it was explained with an EE in the mix (as you have with your hen), bred to a pure bred dark layer (however your roo is not purebred...
You have mixed breed chickens (mixed of mixed) so the rules bend a bit as to development. I find my barnyard mixes tend to mature faster than their pure breed cousins. They also tend to break the color rules as to male or female of the underlying breeds.
I do find comb color the best...