The Color Mauve
You might have seen this pretty, purple color before. It was an accidental discovery by a teenage chemistry student William Perkins. In 1856, Perkins was attempting to synthesize quinine, the medicine for malaria, from coal tar. Quinine was expensive, coal tar was cheap to source, but had many chemical potentials. Perkins managed to isolate the color and create a synthetic dye.
Because of his discovery, the “purple dyestuff marked the beginning of a revolution in organic chemistry, the birth of an industry that has since given us a rainbow of colors, as well as drugs, explosives, fertilizers, plastics, and synthetics beyond measure.” That sounds like a bunch of benefits for something discovered by mistake (JSTOR Daily).