Filtering that reddish color can be done fairly easy
- Transfer image to HSV color space
- Make sure that the H channel is in the range 0-50 or 310-360
- Make sure that V is in the range of 0.3-1
- The final combined mask will probably have the reddish colors
- Now apply a mask and set that mask to white, then merge both images together.
Threshold/range values found here: