I think 'chalk grey' is akin to 'Nardo Grey' or 'China Grey'.
China Grey:
Nardo Grey:
Both look fantastic on the right car. On a RAV4 I can see it being an entirely underwhelming colour choice.
Edit: Actually seeing the picture that PepsiFree posted, I guess that doesn't look too bad at all. I keep remembering the older RAV4 designs which were all yawn-inducing.