Since you said you would be using a camera, see if will allow you to set the white balance. Basically, when you set the white balance, the camera uses a white object (submerged in your tank) to adjust the other colors, using white as a reference point. It creates a setting for taking pics in that particular light. It can be a pain on some cameras though. Further, if your camera allows you to shoot in RAW mode, you can tweak the image colors further using image editing software. I am too lazy to do this myself though. Ha.