You can't get color transfer off of patent leather and it is super difficult on regular leather. Do a forum search and you will find tons of threads on this.
It's a shame I just bought a beautiful Coach patent leather bag and it was covered with black color transfer on the back and some spots on the front. I thought I could fix it and tried every suggestion from people here who are very good with rehabbing bags. It still didn't work, so I just returned it.
Sorry to say but it's shot There's no way to fix it. I learned a lesson the hard way too! Now ALL my patents are stored in their dust bags or pillow cases.