Factual error: The car tags are the same color even after many years Caesar is born. Three years after and then five years, the car tags are still yellow.
Suggested correction: Car tags use a very small number of colors for their stickers. Blue, green, red, orange, yellow are the primarily used colors for registration tags in California, and after some years they start to get used again. Of course the tag colors change year to year, but it is completely plausible that the same color could be used again in the 8 year span that you mention.