I'm surprised this website doesn't count the colorful Windows XP design to Frutiger Aero, although it mentions the colors blue and green as being indicative of the design.
Aero is named for the glossy Aero Glass design of Vista, so XP was like the precursor, before they had the window compositor that allowed such effects. (As others in the thread pointed out, OS X did it first, it could well be called Aqua aesthetic. But I don't think they did blurring in the first OS X.)