Pursuing other XP skin programs, I remembered WindowBlinds from StardockDesigns.com.
For $20, you get the program which redresses your XP system in any of 5,000+ different skins created by fans. I am presently using the “Slate-X” skin.
And get this — it even has a setting to randomly change my background wallpaper every hour! And I can select which images it chooses from, so there is some control! This is closer to a Mac than I’d hoped!
I can also tell it not to skin a particular application — such as Photoshop, which is so resource-intensive that it functions better plain.
It looks like this (but I didn’t use a green background). It is similar enough to XP to be recognizable, but different enough — including transparency effects! — to feel fresh. Plus I really like the orange highlights, they serve as a visual aid when grabbing an otherwise grey scrollbar, for instance (it briefly turns orange and softly fades back to grey when you grab it), and tooltips are in orange too: