2002 passenger plate and emission tab. Non-emission tab coming soon.
At left, this may just be the most scarce sticker ever. Colorado stops producing stickers for a given year about two weeks after that year ends, however many Colorado motorists don't renew their December-expiring license plate until well after that. To solve for this problem, Colorado has come up with what I deem as "overflow" stickers. Overflow stickers are always blue on white - or at least they were in 2000 (at right), 2001, and 2002 - probably because blue on white stickers are easiest for the state to produce.
The reason the sticker at left is so rare is because not only is it an overflow tab (which is very rare as is), it is an error sticker (which I've never seen before). Green on white was the color for 2002's non-emission stickers which accounts for the bottom half of the sticker. Blue on white is the standard overflow sticker colour, which accounts for the top half. Leave it to Colorado to combine them.
UPDATE: (February 1, 2003) Andy Osbourne of Manitoba states that there's a chance this sticker is merely a faded non-emission tab which has been faded somehow exactly along the top-half of the plate only. Due to the positioning of the plate on the car I would guess this isn't true, but it seems just as plausible as an error sticker with two colours. Anybody know for sure?