Pink ink turning brown after laser removal. Is this normal? (photos)

It’s perfectly normal for a light-colored, white-based tattoo ink — such as pink — to darken before fading. The laser energy oxidizes the white pigment, turning it a brownish color. The laser then targets the brown and removes that, too. This double-step process is why removing light colors takes longer than removing dark colors. A board-certified dermatologist who’s an expert with PicoWay laser tattoo removal will be able to remove all traces of your butterfly.

This is normal and expected behavior of titanium dioxide white ink, which is often compounded with other colors to lighten them. Usually on the first treatment, titanium oxidizes to that brown color you’re seeing. With repeated treatment it still goes away, especially with a PicoSure 755nm on a lower setting.
Whenever I suspect the presence of titanium dioxide in a tattoo I prepare patients in advance for its peculiar behavior and reassure them that it’s todally normal. 
Best of luck!