[Heuristx]

You can immediately review the picture on the LCD and simply adjust the white balance and repeat the shot until you like it. Or, if your shot cannot be repeated - the E-520 comes with Olympus Master, which you can use to adjust the white balance when you develop the Raw file. Or, if you shot jpeg, use some photo editing software like the GIMP, which has a white balance adjustment plugin. Noting is lost, there are amny pieces of software that can either set your white balance(thst's the easy way) or the color balance(hat's a bit fussier a process).