If it hasn't shed yet, it's probably just as GreenTea says; they change colors throughout the day. Here's two pics of one of mine at different times. The color change can occur in a matter of minutes.
As for the book, the one mentioned by someone else in this thread is awesome. You can also find it at giantgeckos.com. It covers all rhacs, but the pictures are worth the $40 price alone. There will be another book coming out soon and I think it focuses on Cresteds only. It should be around $10, I'm told.
Here's Kirby cooled down

And here he is fired up

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Rob Jenkins
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