That wasn't spelled out perfectly in the post. The answer is that the set of crayon colors (e.g., red, blue, purple) is fixed and known to all parties. The only

That wasn't spelled out perfectly in the post. The answer is that the set of crayon colors (e.g., red, blue, purple) is fixed and known to all parties. The only thing Google gets to swap is the ordering of which of the three colors it uses to color in each vertex. If I pull off a hat and find an illegal color -- e.g., hot pink, no color at all -- then I know Google is cheating.