There is a Color Balance option on the Enhance Photo drop down that should be on your starting toolbar. Within limits, you can use that to fix White Balance. Since you have backscatter, the indication is that you used the strobe; if you were close enough, the color balance will work fairly well on jpgs. When I bought PS Pro X, you could additionally get Pixmantec RawShooter Essentials. With a C7070, you can shoot raw mode, you should do that, and use Pixmantec to do the white balance - its 16 bit vs. 8 bit per channel, you're chances of saving a shot are better. You can then export the raw mode to jpg and use PS Pro to do clipping and other edits.
As far as backscatter is concerned, there is a clone brush that you can use to select the color next to the backscatter. If you have a limited amount of backscatter, it can do the trick. But there are limits, mostly to your patience. Its far better to get a shot with little to no backscatter. If you are getting large amounts of backscatter in your typical dives, consider going "no flash", and then using RAW mode and white balancing the photo (this is assuming you have enough light, and aren't too deep). Or, consider getting an external strobe if you're using the internal strobe.
For what its worth, I don't mind having a little bit of smutz in my shots - I feel like it gives the feeling that you're actually underwater (I don't think I've ever been diving with absolutely crystal clear water, although PNG was close). If you have a ton of backscatter, you're best bet is to keep the shot, remember why you had so much backscatter, refer back to it on occasion and remind yourself not to do that in the future.
To get an idea, the attached was taken with a Nikon 5600 with the internal strobe on (bad idea). I forgot I had the internal strobe because the shot before that required it, and, harbor seals don't exactly give you a lot of oppurtunities so you have to get on them quick. I got a ton of backscatter, especially around the eye. I screwed around with it in PS Pro X, using the clone brush and color balance. Its better, but still not what I would consider a keeper. It will stay around because disk space is dirt cheap, it will still jog my memory of the seal, and it will remind me of my screw-up (should have had the strobe off and used manual white balance, there was enough light).