Another thought if your trying to recover this particular photo. You should notice a reed red ring around the sun. This ring is the color of the sun just before the sensor saturates. Even though the sun is deep red, there is so much luminosity that it blows out the sensor in all color channels. You can recreate the color in PS by creating a fill layer and filling it with the color of the red ring. You can then brush the color back into the sun. I've done this on occasion and it's lent satisfactory results for me. Be careful not to cover anything in front of the sun such as a cloud, tree branches or a layer of haze.

Just a suggestion
Mike