Some valid Green Cards have no date on them (most do), but are valid for ten years from the date issued. Before the expiration date comes around, you are expected to renew your green card. If you forget, you will not lose your permanent resident status, but it’s important that you act quickly. If your card has no date, you can assume it is expired and apply for a new one.
The ten-year validity of a green card does not apply to conditional permanent residents. If your residence is conditional, not only will your green card be valid for only two years, but your permanent resident status will expire along with the card. To prevent your status from expiring, your will need to file the appropriate paperwork with USCIS, as described under "Conditional Residence for Recent Marriages."
USCIS began issuing the new, colored card on May 11, 2010. In addition to actually being green in color, it is also redesigned to deter immigration fraud. USCIS incorporated state-of-the-art technology into the new card, which prevents counterfeiting, obstructs tampering, and allows for quick and accurate authentication. The cards now replace the old green cards in circulation upon renewal or if you apply for a replacement card.