Old Ivory was the last of the original five colors. It’s neutral tone was meant to pair with all of the colors but not clash. While most people know that the original red was made with uranium and was thus radioactive, not many people know that this ivory color was also made with radioactive materials. However, the amount of radiation this color gives off is minor, especially when compared with the radioactive red.
Old Ivory, which is what it was actually called in 1936, was fired from 1936 to 1951, when it was retired for the 1950’s colors. Today, it’s mostly called vintage ivory.