Kassia St. Clair is a British author and journalist. She is best known for her book The Secret Lives of Color, which explores the history and science of color. She has written for publications such as The Guardian, The Economist, and The New York Times. She is also the author of The Golden Thread: How Fabric Changed History, which was shortlisted for the 2019 Cundill History Prize. St. Clair is a passionate advocate for the power of color and its ability to shape our lives. She is a frequent speaker at conferences and events, and her work has been featured in numerous exhibitions. She is currently working on her next book, which will explore the history of pattern.