[rotorwrench]

Soy bean plants can broken down for quite a few uses. The soy bean oil can be refined down with a polyol being one of the by products. Polyols can be used in the manufacture of polyester plastics that have a wide range of uses. The soy plant fiber makes a very good filler or reinforcement materiel in the manufacture of phenolic plastics similar to Bakelite which is phenol with formaldehyde. Bakelite can be made in quite a few different colors. I have no idea why they were changing colors around but there could have been a good reason in the war time era with shortages of all sorts of materials. Carbon black was in short supply.