I read this, yesterday as I was trying to figure it out as well....some is repetitive to what JoeBar said. Mostly depends on who you get at DMV as I had 2 buddys who bought Yamaha Blasters 2-strokes last year one bought a used 99 model and got issued a Red sticker the othe bought a new 2002 and was issued a Green?!
OK Here is how to the Red Sticker Works:
OHV's manufactured after January 1, 1997 must meet emission standards established by the California Air Resource Board (CARB). These regulations prohibit models that do not meet the standards from being issued Green Stickers by DMV. Currently, no two strokes meet these emission and only a few four strokes (Honda XRs, Suzuki DRs, and a few others.) The non compliant bikes are supposed to have a "C" or a "3" as the 8th digit in their VIN Number. These bikes are supposed to get Red Stickers. Operation of a Red Sticker vehicle outside of that area's approved season is a violation of Title 13 of the California Code of Regulations, section 1412 (f).
Which bikes should get Red Stickers and which Bikes Actually get them:
All new bikes except for the few that meet the emission standards should get Red Stickers, but that is not how it is currently working. Depending on which DMV you go to or the DMV employee that does the paperwork on a new bike, a new bike may receive a Red Sticker or a Green Sticker. Currently when buying a new bike that was manufactured in Japan, there is a chance you may end up with a green sticker even if it does not comply with CARB regulations. Almost all European Manufactured bikes are still getting Green Stickers even though they are non-complying. This may be in part due to the fact that the VIN numbers do not match the standards set for non-complying bikes. Basically buying any new non-complying bike there is a chance of getting a Red Sticker and a chance of getting a Green Sticker because the DMV has not yet figured out how this program works.
If you do get a Green Sticker for your non-complying bike you will probably continue to receive a Green Sticker when you reregister it. If the DMV does catch on and give you a Red Sticker there is nothing you can do about it. If you are accidentally issued a Red Sticker for a complying bike go back to the DMV and demand a Green Sticker.
The difference between a Red Sticker and Green Sticker:
A Red Sticker and Green Sticker are very similar, they are what you will receive when registering your bike with the DMV and cost the same. The difference is that bikes with Green Stickers can be ridden year round at any public riding area. Red stickers can not be ridden during certain parts of the year at certain locations. The riding seasons for Red Sticker bikes vary depending upon the riding area. Some riding areas are open year round to Red Sticker bikes and some are only open for 2 months depending upon the air quality for that area. All closed courses, tracks, racecourses, ect. are open to Red Sticker bikes.