Cat Urine Bleached Leather Couch?

I have a leather couch that our cat decided to use rather than the cat box. Unfortunately, there are a few areas that the urine or vomit took the color out of (merlot color). I've cleaned the couch and replaced the foam cushions, but is there a way to re-dye the areas that seem to be bleached out and are a little rough feeling? I've tried shoe polish, but it didn't work. Thanks!