DaveB;4672568; said:
But is that work that you did PP retaining an accurate set of colors?
I'd say so. Accurate in terms of what the fish would look light under true sunlight I would say. If you look at the before, it's easy to see there are some bad white balance problems, unless you have a red light over the tank! White balance is just that, making whites look white, regardless of what spectrum of lighting they're under. I try to keep this in mind when making white balance adjustments. I try to adjust the colors to what they SHOULD be under natural daylight, instead of how they 'looked' under an blue fluorescent bulb - because that is NOT an accurate representation of its true color.
DaveB;4672568; said:
But if the good flashes overhead still produce realistic color that's all I need to hear.
Yes, they do. They do a good job of giving accurate color. But I wouldn't say it's perfect. There's been few times where I've seen my DSLR give me accurate white balance, regardless of the lighting. Setting the white balance to AUTO does a decent job, but it will vary from shot to shot, and isn't always right.
On the flipside, here's yet another example of how cameras and flashes don't always get the white balance right. A camera's flash is color-balanced at pure daylight, which is about 5500K. Depending on what light you're under, the results of using flash can be very blue or very orange. If you're shooting outdoors under pure daylight though, the flash will balance nicely with the ambient light. But incandescent, tungsten, and fluorescent lighting will give you wonky results, both with and without flash. And I'm using these as examples because it applies directly to aquarium photography as well.
This pic was taken at AUTO white balance, with the speedlight bounced up into an overhang behind me. Generally speaking, most would be happy with the results, but there are some serious white balance problems here:
BEFORE, compressed jpeg, straight from camera
AFTER, shot RAW, processed in photoshop