We have a sony DSLR digital camera.
Its all in the White Balance. None of the preset "Incandescent", "Sunny", "Cloudy", "Fluorescent" type of settings work in the tank.
What we do is set the white balance in the custom WB menu. You basically take a picture of something white in the tank so the camera knows what is white. It even tells you the Kelvin temperature of "white". In our case it was 9900K.
After you do that, the camera knows what is white in with the bright light and everything else looks accurate.