i wish i had a windows pc just so i can use that program, but i know nothing of it... i use www.minecraftskins.com/editor.php?image=skin_2012111623583635687.png for my skins, it provides a 3d character to dress up and the abiltlity to use either "z" to darken a color, or "x" to lighten the color. which makes it pretty easy to shade. and if you wanna get super shady, place one color then change the darkness my about half of what the z and x buttons do and place it next to it, then select the first color by clicking the scroll button in and then shading it skipping a line and switching to the other, thus creating a smother shade!