There is nothing that would lead to any harmful interactions with red light sessions and tattoos.
The Beauty Angel generates light energy primarily in the near infrared and visible regions of the light spectrum (non-UV). Because these are never stronger than natural sunlight, unwanted side effects like fading of tattoos are very unlikely. However, if any symptoms occur that could indicate an incompatibility, you should stop use this type of light treatment. As always, if you have any concerns about using the Beauty Angel, you should consult with your physician or other healthcare professional.