I know there are a couple of USS Lakotas and Defiants on BCFiles. You could also try TrekCore.com to see if you can find some clear shots of the two ships with their phaser arrays/emitters. Otherwise I would suggest going to Suricatafx. He has a Starfleet Color Reference chart available. It has colors from the Sovereign, Intrepid, Excelsior, and Excelsior Refit.