Many may be familiar with this site, but just in case. I found it while kicking around in Britmodler trying to dig up more details on the Defiant night fighter finishes.
The main site covers a lot of subjects -
Reference - the more interesting for me was the Camouflage And Markings page -
Camouflage & Markings
There are other pages that will be useful, to me anyway, since it appears that most every craft has been addressed and discussed in detail?