I think you guys are both right in a way.A quick review of reference books by Wayne and Scott mentions two poles other than the banjo.One,called the shepards staff was the early one (20's)and was only 10'tall.Darin,that one may be what you are thinking ab ot with the 42"sign.Then later they used a side mount pole with the 72"signs that Kevin mentioned.When we see a pic,I suspect that it will be the side mount version,18' tall.
Anyway,back to his question,I personally have never seen a tall Texaco pole painted anything other than white.