I recall that my grandfather would go to the gas station and buy "white gasoline" to use in the older Coleman stuff he had (a lot of years ago). White gasoline was also called "unleaded gas" back in the day when leaded gas was the standard.
White gasoline at that time did not have any additives so was very similar to Coleman fuel.
You may be confusing the old "unleaded gas" (white gasoline) and today's unleaded gas.
I respectfully beg to differ.
Back in the 60s and 70s when I was a mechanic in a a gas station, we sold White Gas, and the following comments apply to knowledge from those times, straight from our fuels supplier.
White Gas is NOT a motor fuel. It was never rated to be. It would have been highly aggressive toward fuel system components in use at the time. White Gas is only 35 to 40 octane which makes it highly volatile and very dangerous to handle.
Avgas was an unleaded motor fuel, and came in 85, 100, and 140 octane. Standard leaded pump fuels at the time were 95 and 100+ octane.
When we were asked what made the White Gas that we sold different from Coleman fuel, we were to answer "Well, besides it being about a third to a quarter the cost, our White Gas has some oils in it and may have a tiny bit of sediment in it that you won't find in Coleman fuel. If you strain it through a handkerchief when filling your Coleman appliance, it will burn exactly the same as Coleman fuel."
There was no such thing as "Unleaded Gas" in those days. If you wanted motor fuel without lead, you bought White Gas or you went out to the airport and got Avgas.
Since I worked for Shell at the time, I can tell you the Company introduced "Shell of the Future" which was 91-octane unleaded motor fuel ... in 1970. We had a tank put in for it not too long afterward and were selling it then. And that's when it got the name "Unleaded".