Proper noun
the Southampton Six
(informal) Six artificial food dyes, a mixture of which was studied by researchers at Southampton University (results published in 2007), who found a possible link between these dyes and a sodium benzoate preservative and increased hyperactivity in children consuming them. The dyes are: tartrazine, Allura Red AC, ponceau 4R, Quinoline Yellow WS, sunset yellow, and carmoisine.