I, too, am disturbed and distressed and dismayed by this washing out of color in the GUI. I have to really stop and think all the time, now, to make sure I am clicking on the right button or icon.
And I have been thinking about it some. I wonder if all this change is just a way of prodding us all to move away from the traditional Finder-folder model and instead, adopt Launchpad and other perhaps related additions to the system. Launchpad, you'll notice, is about as colorful as you can get, with big, juicy, distinctive icons. And with apps able to re-open with their last file ready to go, and with Time Machine and with the ability to browse files a la iTunes album covers, and perhaps more, who but power users needs to be working the Finder and its folders and files?
Just a thought.
Still, to me, it all looks quite arbitrary and for-its-own-sake. A severe case of iPod-itis, anyway.
I remember the serious criticisms when OS X apps took on that brushed-steel look, doing away with a much simpler and easier-to-use design. Who knew that was only the first step to Lion's absurd world of gray?