Toxicological Trivia from November 18, 2009: The human species has suffered direct or combined effects of dioxin and other substances with significant impact on the Vietnam War. Orange, pink and green agents were all herbicides used in Vietnam and that contaminated the country in varying degrees. What color of herbicides was not included in previous list?
a) Purple;
b) Blue;
c) Yellow.

Answer a. Read more in Spanish FAQ: What is Dioxin?