I'm very interested, as I have the 2 Alfa-Romeo 8C 2300 FPP Modelos Le Mans 1933 and 1934 in my stash.
Always problems of color on these very ancient cars.
The 1934 was blue, as a french owned car.
So I made some research for the 1933 one.
If the rear was obviously red, the color of the nose is not known with certitude.
Some specialists think pale yellow and others think bright yellow.
So, it's up to you ...