I've seen the fake ones and they'er really not that close. Especially, if your used to looking at license plates a lot.
I don't think you'll fool to many cops with them.
I year or so ago I tried to 're-produce' some actual Cali black & yellow plates.
For display purposes only, of course.
We still have a few black blanks from 'back in the day' and the yellow ink can be matched.
But I found out, much to my dismay, that we no longer have the dies that were used to press them with.
The dies were sold for scrap metal a few years ago! They were there on the die rack when I left the factory 4 years ago, and now they'er gone. Cali no long has a means to re-produce them.
I could make them look close, but not exact. The cost to re-build the dies would be about $15,000.
jdog