Thanks! Got a couple of email responses too, adding a bit to this puzzle.
Actually, The Ethyl Corporation tells me that in the beginning, there was no legal requirement for gasoline with TEL in it to be any colour. It was legislated later. And some gasoline had more lead in it than others, and octane testing in the early era was "iffy" at best.
TEL does not in itself add colour.
I'm still waiting on more info from Ethyl.
I have a credible story about a fuels distributor for McCall Frontenac products getting together with a dyemaster at a local fabric mill, and coming up with a hydrocarbon-stable red dye to put in his high-test to differentiate it from his regular gasoline. Of course in a visible pump, this would be quite apparent.
The story is that it was added to a delivery tanker and sent out to several local atations as a test. The tanker was emptied, but the next time it was filled, residual dye left in the tanker from the test coloured the next delivery lot, which was sent to towns farther away who were unaware of the test. When the gas was delivered, it caused quite an uproar at the stations as it was an unfamiliar red colour.
This distributor used red dye in his premium right up until blue dye was legislated as the standard. Again, I'm waiting for dates on this from the government. Should show up sometime this decade, I'm told.
(Interestingly, this distributor also sold a brand of gasoline containing oil, under the brand "Sun Lubricating Gasoline". It contained 3% oil, and was yellow. Apparently, it was not uncommon to add oil to a tank of gas for top-end lubrication.
This company no connection to The Sun Oil Company in the United States, and is a precursor to Suncor in Canada. Sort of.)
Prior to dying gasoline, there were plenty of accounts of unscrupulous dealers selling two brands of gasoline - from the same tank...
And the price differential between the two was originally quite high - around 25%. When regular was 3 cents per gallon, premium was around 4 cpg - so this could be quite lucrative to the crooked dealer.
[This message has been edited by silent chief (edited 03-09-2006).]