yellow and black; the devil's livery
The colour yellow traditionally denoted quarantine, and black denoted death. Together they were called the devil's livery. Livery was the uniform of a servant.
yellow fever, yellow jack
An acute infectious disease of tropical and subtropical climates, characterized by fever, haemorrhages, vomiting of blood and jaundice. It was the first human disease identified as caused by a virus. First reported in Antilles in 1635, a vaccine was eventually developed by Max Theiler in 1937.