I use GraphicConverter on a Mac to tweak my photos before uploading to share. Typically, I'll brighten or adjust a shadowed area or contrast, that sort of thing. Sometimes I'll hide a defect (such as a person who walked in front of a shot) by copying adjacent background over the top.
Is it possible to darken gray hair with GraphicConverter? I've tried selecting the hair (using either lasso or polygon selector) and then darkening the selection or adjusting the gamma, but this always ends up with a sharp line around the selection.