Armour Yellow was a standard color. When chromium was removed from paint, the struggle began. It is almost impossible to match older yellow colors, even with factory formulae.
AN Yellow Orange was a standard color for WWII aircraft trainers. I have tried everything to match it. I come close, but never get it "on the money." Anything painted before about 1995 cannot be matched exactly.
I agree - always use white under yellow. Always!
