On the 17e of September Google changed the connection and authentication method of ther api for the Google Calendar data.
After a fresh install of Firefox and THunderbird on Ubuntu Natty the colors of indexed images and icons are mangled.
Jena said on this page http://ubuntuforums.org/showthread.php?t=1742738
Re: (some) colors shifted after Natty upgrade
Also, I checked on another computer - the screenshots I posted above are accurate. Those are really the colors it shows.