First off you must use a Q switched laser system for tattoo removal
Black and Grey are the easiest ink colors to remove. Usually, a Yag(1064nm) laser works well for these)
Green is the most difficult followed by light blue (Yag and Alexandrite lasers 1064nm and 755nm).
Red/brown/yellow/orange respond well in my experience primarily using 532nm laser.
The bottom line is you can usually clear a tattoo to a level that is barely noticeable to the naked eye, it's just a matter of how many treatments it will take to get there. That's because of the great variability in ink composition and our own individual immune systems which is actually what clears the ink.
Hope this helps,
Dr D.



