Not my favorite color.
The creation of Prussian blue was the result of a simple error by two German alchemists, Jacob Diesbach and Johann Konrad Dippel. While mixing a batch of cochineal red, Diesbach was alarmed to discover that his concoction had turned a deep blue. After much investigation, he determined that this was the result of a chemical reaction caused by animal blood found in contaminated potash provided by Dippel. The world’s first synthetic pigment was born.