Some people perceive the color or shading portions of the tattoo to be more painful, however this is not because gray or colored ink is any more painful than black ink. As other have mentioned, usually a larger group of needles is used in shading and coloring as so the artist may cover more area, rather than an outline, which (if it is a thin one) may have only one or a couple needles. There are very few tattoos out there that are just outlines though, as most tattoos (whether color or traditional black and gray) have some form of shading or filler, making the vast majority of all tattoos equally as pain-inflicting. One example of how a non-colored tattoo could even be more painful than one with color would be large tribal designs, in which many needles are used as once, more than what would would be used for a small or medium colored tattoo. In short: it is the number of needles, not the color of the ink... that bothers some people. Personally? I don't feel a significant difference between outlines and shading/color. As for your ankle being more painful... perhaps, again- as others have said- the closer to the bone your tattoo is, the more painful many people find it to be. Everyone is different, their experiences, their pain tolerance, their artist's technique, etc. so no one can accurately describe to you how your experience will be. I can, however, tell you that the majority of all people I know said it is "not as bad" as they expected.