tombstone signs

[round2it]

Hello all, I'm looking for a little knowledge. I've seen many vintage quaker state tombstone signs with green background and white lettering. I'm in the process of purchasing a tombstone with white background and green lettering. It also comes with the original frame its mounted in and swings from. Could anyone tell me why it has the different coloring? Or if the company even produced them? It certainly looks original, but I'm a complete beginner at this whole new collecting world. Any feedback would be greatly appreciated. Thanks