A puzzlement

I've recently seen, on a couple of cars around the Bay Area, a sticker featuring three squares in a row.

One square is red.

One is green.

The middle one is white, with a menorah on it.

Mexican Hanukkah?  Italian Hanukkah?

I find the question asked on the Web, but not answered: what is it?

Or is the emblem in the middle not meant to be a menorah at all, but something else entirely?  The White Tree of Númenor, perhaps?