And again you are
LOL (
)
The cham changes colour primarily (if I am not mistaken) because of mood. For instance a very stressed chameleon will display a dark variation of their calm colours, a basking cham will show lighter colours, and the true colour change comes when fired up. For instance, if a male sambava panther saw another male or wanted to court a female and his resting colours were dark red, to show dominence he would display his 'fired up'colouration. Sambavas can turn orange, red, yellow, green etc.
A lot also depends on genetics/species. A chameleon from a poor genetic line may not show the colour intensity of a chameleon from a strong line. That is not to say it wont change colours, but perhaps not so brilliantly.
Speceis also plays a role. Panthers tend to be one of the better colour changers out there. Veileds for instance dont change colour all that much. An excited veiled mght display a brighter version of the colours it has whereas a panther could turn from totally green to totally red.
Example of my male Maroantsetra panther chamleeon Max. (Pictures taken within a few weeks of eachother)
Normal Colouration (8 months)
Just woke Up (9 months)
Fired up (9 months)
Right now he wont get fired up .. he is the friendly giant of the chameleon world but when he sleeps he turns a bright red colour, and his resting colours ar essentially the same.
Hope this helps to clear things up a little.
Jason