Farmall Cub

I am restoring my F-20 Farmall it is a 1938 model with cast center wheels which has the bolt on rims front and rear my question is, what color should the rims be painted. Thanks in advance for your answer.

In 1936/37 they changed the colour scheme from grey to I.H. red with silver rims, just the rims not the clamps or bolts.