I may have been looking at this too long, or am missing something. I can not get this one figured out. What am I missing?

Of course I see what I was missing the second I post this.

Ok, I was wrong, I still can't get it.

Any help?

I should hang it up for the night.

This one was tough for me, but I think think you may have done what I did on the mauve rule. In C; there is Iguanadon = green, Plateosaur = yellow, Stegosaur = red, the rule for Lambeosaur and Ultrasaur is the if both, 1 is NOT mauve. I missed that and wrote the constraint as; if both L & U then...