You both correct and incorrect. You are correct about the color changeover. But the staggered registration did not begin in California until January 1976, so before that, only a single year sticker was issued, with the location alternating L and R. The 1969 sticker was supposed to go in the left well, while the 1970 sticker went in the right well. Now that the state has staggered registration, the month sticker lives in the left well, and the year stickers go in the right well. If you look on ebay, you will see pre-76 plates with no monthly sticker. A "natural" plate will only have a single year sticker, meaning it was issued during the indicated year. These are the ones that license plate collectors seek. I have been collecting plates for ~50 years, and have a nearly complete set of natural Calif plates. Am reducing my inventory, which is why I offered the above plates for sale. I also have a beautiful pair of black 1969 Calif plates -- so it has a single 69 sticker in the left well and no other stickers. $100 plus postage.