Tattoos flake and peel much like a sunburn. In the case of color tattoos the flaking skin will be the color of the ink below and many people (especially first time tattoo clients) think their tattoo is "falling out". This is completely normal and right on schedule.
Give the tattoo ample time to completely heal (about 4 weeks) if at that time you still think it needs to be touched up then just contact the artist.
Most if not all of the artists here will touch up their own work free of charge. I hope that helps,
-Ed