80/87 Octane. All the <120 knot aircraft ran it. When it dried it coagulated, kinda like blood. Little did we know it sealed small leaks in the fuel tanks/bladders. When 80/87 was no longer available, the shops were full of aircraft leaking fuel.
I can still remember avgas 91/98 Brown fuel, 100/130 green fuel, abd 115/145 purple fuel.