What's the best way to downgrade?
Since I do a lot of "messing about," I often need to go back to an earlier skin version. For the bundled skins, instead of puzzling over which version I'm getting when I select the skin in the app, I just start off by deleting any and all copies of the skin.
Tools > Open directories > Open config directory and delete skins/NameOfSkin. Then open the
program directory, and do the same. Finally, install the version I actually want to use.
When I'm done tinkering, it's an easy matter to reinstall the latest version from the skin page on the site.
Also if downgrading: What happens to my settings in the latest version? -like colors, fonts etc etc..
That's where things get tricky. If the skin developer hasn't made a bunch of changes to the available settings and their internal variable names, you're pretty much safe. When you open your saved project file, all your new settings will still be there. But if there have been extensive internal changes to the skin (something I try to avoid in my own skins, for exactly this reason), you might find that things need resetting, or that some of the settings in the newest version simply don't exist in the earlier version.