Paint on these tractors is a mystery.
I have never found a source that knows all the colors and years for sure.
One source I have says the first orange used was this one:
Allis-Chalmers Dupont Dulux 008 for a match
1929-1948 Models 25-40, United, U, All-Crop, UC, WC, WF, A, B, RC, C
1949 through 1960 Dupont 29047 for a match
so called Persian Orange 1
1961 0n PPG 60396 for a match so called Persian Orange 2.
There was also another orange called Corporate Orange for the heavy equipment.
Who really knows????
If it was mine I would find a Persian Orange 1 and Paint it.