Originally Posted by rdraper
From travel.howstuffworks.com
"The previous U.S. passport (the one before the 1994 update) featured a green cover and included a special one-page tribute to Ben Franklin in commemoration of the 200th anniversary of the U.S. Consular Service. The cover of the new passport has reverted to the traditional blue color but has retained the woven cloth material used in the green cover."
I had one of the green U.S. passports until '03, when I had to have it renewed (and got the blue). Liked having the green, because I could quickly tell the difference between my U.S. passport with the green cover and my Latvian passport with a blue cover.