Twitter has lot my (and several others too) profile photo. The main page look like:
The default user icons are shown instead and here is a sampling:
What color is your default icon ? 
Alex says it’s not intentional.
UPDATE:Root cause of the problem identified.
Technorati: twitter
Mine isn’t one of those you’ve got there, its a darker blue closest is the green one on the left.
Comment by ch8rt — September 18, 2009 @ 6:51 am
ch8rt, feel free to post your colored icon for a complete collection
Comment by arungupta — September 18, 2009 @ 8:45 am