Don't think there's any automated way to do it, but: As different B&W films different color responses, I would highly doubt it. The older films see red and black the same, they just did not respond to red at all. Hense the red "safelight" in most darkrooms. one way to do it might be "Ultimate Paint", a Google search should show it up somewhere, and it's a freebie. Might take a little playing with to learn to use the threshold windows, which are very tiny and on the lower toolbar, but it can detect different shades of any color, and replace it with another. Colorizing isn't easy no matter how you do it.