I've posted a test version of HeroMachine 3 here featuring the first pass at the "undo" feature for those brave enough to give it a whirl. This test version shouldn't affect your "real" saved characters at all, they're totally separate files. But caveat emptor and all that.
It's pretty much what it sounds like -- do stuff and if you don't like how it turns out, click the "Undo" button:
It'll undo until there's nothing else to undo. Color changes, scaling, rotation, moving an item with either the mouse or the transform buttons, alpha changes, deletions, additions, "color all skin/hair", "Clear All", you name it, you can probably undo it.
Currently there is no limit on how many "levels" of undo there are, but I'll probably need to cap it at some point.
If you've a penchant for life on the edge, I'd appreciate your trying it out and letting me know how it works for you. Hopefully we can work out the bugs in this and then, when it's ready, make it the "real" HM3 alpha for everyone to use. I particularly want to make sure it doesn't mess up saving and loading of characters, so if you can check that out that would be great.
Edited to Add: I'll be taking down the "C" test version from a few weeks ago in a few hours, so if there's anything you wanted from it, you better get it asap.