Color Underwater
If you have an underwater picture that seems to be the wrong color you can correct that color with photo editing programs that are available for your computer. There are a large variety of these programs. The most popular photo editing program in professional circles is called, Adobe Photoshop CS3. A very expensive program, though there are more reasonable ones available.
Every photo editing program is different. To correct the color of a photograph, you have to find the color correction tool. Some have automatic color corrective tools, some are manual. You will have to use the help tool on the program to find out how it is done. This method of correcting your colors is not always the best way to get the correct colors. I don't know if you know it or not, but all pictures taken underwater without a flash start losing color after the first 10 feet. The first color to go is red. Then you will lose the red plus green (about 60 ft, and then you will lose the red, green, and the blue. That's when you're about 100 feet down. Your picture will look black and white or a real dark blue, if there is no other light at that depth. Red, blue and green are you basic colors in photography. So as you lose those colors, you will lose all the other colors. As you descend your brain will be fooled and you will think you see the missing colors, but your camera can't be fooled. Besides at 100 feet unless conditions are perfect, you won't have much light to deal with.
Of course the color of the sky and the condition of the surface makes a difference too. That is why I usually use a flash. Two flashes are better than one. The flash though is only good for about 6 feet or so, depending on the strength of the flash and the f stop you are using. You have to keep the flash as far away from the lens as possible so you don't get backscatter. Backscatters are the little particles of gunk in the water.