To show true colors you will need to have the correct white balance. Depending on your camera you should be able to set this by first shooting a neutral gray card then setting it as your default. Or a simpler way is to do as Captbogart suggest and get some full spectrum (available at home depot and Lowes) fluorescent light bulbs then set your white balance to match the color temperature (5500K I think). You can also buy some very inexpensive reflectors from home depot and Lowes and put the bulbs in them. Shine the lights on the snake and turn off all other lighting. Shoot the pic and it will turn out nice.
The worst lighting is if you are trying to shoot in a room with blue or orange cast fluorescents it is almost impossible to get a correct white balance. A mix of different lighting also makes it hard. I have found natural sun light to be tricky as well since depending on your back ground and surface you can get color reflections that throw off the white balance.
That all being said if you have a good camera you can use its preset white balances(flash, natural sun, auto white balance, ect) and then tweak the picture in light room, Photoshop or some other similar photo program to match the correct color.
Here is an example of camera controlled white balance. I took this pic with my Canon 50D and on camera ex 580 speedlight with gary fong diffuser attached. The snake is over an ink blotter on my desk. I set the white balance to "flash" and shot the pic. I then processed the raw file in light room however I did not have to adjust the white balance at all it came out exactly correct.