I’m definitely no photographer but for getting as close as possible to their “true” colours, I personally like direct sunlight. Bright white LEDs are ok too but tend to look kind of blue to me. You can also play with the white balance and brightness settings in an image editing program. As long as you don’t go overboard, I don’t consider this “photoshopping”. It just brings them much closer to real life (and not just with snake photos). I find it especially helpful for iPhone pics.
Also, a trick I learnt from field herper friends is to place them in a hide then remove it at the last second before you want to take your snaps. It will result in them staying in the one place for a bit longer so you’re not trying to chase them and should result in less blurry images.