ha! this is something really cool about your gecko. cresteds are sort of like mood rings. when they're active/awake/excited/gettin' busy, etc, they are "fired up". this means their colors are darker and more intense. when they're sleepy/cold/mellow, their colors are much more pale and they sometimes even look washed out.
my patternless red, Xochitl, fired-down and sleeping, is a pale creamy orange like tomato soup + milk. when she's fired up she looks like ketchup.