99.999% of people would never notice this nor care about it, but a Google Webmaster Help thread has discussion around a very small bug in Google's cache. If you view the cache of a W3 document for a match on xml well formed root, you will notice that Google says they will highlight the words "root" in a red color. But if you scan through the document, you will notice Google is not highlighting that word in red.
Here are pictures:
Googler, JohnMu, thanked the person for reporting it and has submitted the bug to the right team.
I am shocked that it was reported and noticed.
Forum discussion at Google Webmaster Help.



Comments:
Barry Mitchell
07/21/2009 09:59 pm
for ages i have been trying to work out what google thinks of my old cached pages and how to improve my rankings according to what i see in my cached pages. I really don't get the coloured and highlighted text.. the colours make mo real sense to me... advice is slim from google and this is only to be expected. I have good rankings, but i would like better and assessing the colours of the cahed pages might help.
No Name
04/13/2010 06:09 pm
It you type our name in Google Search then add some of the description Google shows and research, once you visit our home page, you notice something very cool.