I’ve worked with a number of photographers with red/green color blindness and helped them color correct their images reliably. What’s most important is to master the use of the Info panel in Photoshop or the RGB color picker in Lightroom. Equal values of RGB will always create a neutral shade of gray. By measuring neutral colors in the image and viewing their RGB values, you can determine what, if any, color cast is present in the photo and adjust accordingly.

For a step-by-step color correction tutorial in Lightroom, you might check out the 2nd edition of my book Perfect Digital Photography. To perform these steps in Photoshop, and read a more detailed description of the use of the Info panel for color corrections, you might check out the first edition of my book.