Fortunately she knew about Firefox's "View page info" menu item (right-click on the page to get it) and used the Media tab there to discover that the logo she was seeing was: http://www.google.com/images/srpr/logo1w.png.
Asking around and googling for things like
google logo change
google different search page got me nowhere.
tried turning those both off but still didn't see the page she saw
(though turning off JS did get rid of the annoying fade-in effect
Google started using recently).
Running out of ideas, I Googled for the filename of the logo she was seeing: google logo "logo1w.png" and that turned out to be the answer. I found discussions on reddit and NeoGAF, which led me to articles on SE Roundtable and search Engine Land comparing Google's UI to jazz (you never know what you're going to get next).
Following links eventually led me to an article on the official Googlblog, explaining how Google chooses random users as guinea pigs for trying out new user interfaces.
Unfortunately, none of these articles gave a clue how my friend could opt out of being a guinea pig and get back to a page where the search box colors didn't hurt her eyes.
But it turned out that it's cookie based. So if you find yourself stuck with a Google test page you don't like: Delete all your Google cookies. That did the trick for my friend, and got her back the standard interface.
The Googleblog article (which is full of interesting facts, as
Googleblog articles often are) also led me to suggest another tip to
her. Apparently a lot of this UI testing is based on how long it takes
users to type their query into the search bar. So if you get selected
as a test subject and you really dislike the UI they're showing you,
typing very slowly might be a way to make it clear that this UI is
not working out for you.
[ 16:03 Nov 24, 2009 More tech/web | permalink to this entry | comments ]