Light Brown Tattoo turning red? (photo)

The situation. I went to one treatment center for my first 3 sessions (all spaced between 6-8 wks) and the Dr. did not want to touch the light brown ink in fear of it changing color. I've switched to another Dr. and we decided to treat the light brown ink. Now, as you can see after 4 treatments to the brown ink... it's turning very red. During my last session, they decided to try another wavelength. It's only been a week but it's still red. Thoughts? Thanks so much