[citation needed] Denim is usually dyed with natural or synthetic indigo. The quip about the navy refers to Methylene Blue's pharmacological use as an antimalar

[citation needed] Denim is usually dyed with natural or synthetic indigo. The quip about the navy refers to Methylene Blue's pharmacological use as an antimalarial drug. https://www.researchgate.net/publication/49831954_Lest_we_forget_you_-_methylene_blue https://www.researchgate.net/publication/49831954_Lest_we_fo...