So using constant correction everywhere cannot be perfect. The correction must also vary with intensity. It takes some experimentation. This exercise is to scope out the details that we can learn, to have a better clue. The Curve Tool is extremely good for this because the needed correction is not linear.
Several programs have a Curve tool, it is a standard tool.
This is Photoshop, and most scanner twain drivers will furnish one too. Removing Red makes the image darker, and we run out of range too. So we add Blue and Green instead. To do that in this case, I boosted both of the Green and Blue channels of the Curve Tool as shown above in the Green channel. I left the Red channel alone.