A bright enclosure is the best trick for good colors. Often times a single Reptisun and a basking bulb are not enough. Walk outside on a sunny day and notice how you almost instantly squint your eyes. Now stick your head in your beardie tank...not nearly as bright. It takes a good deal of wattage to replicate even a partly sunny day, so consider adding additional lights of the proper spectrum to your enclosure. A fluorescent bulb ranging from 5000-6500 kelvin is the best way to approximate sunlight, and if you can mix and match spectrum's it would be even better.