Patent Blue V Colour Shade Synonyms Food Blue - 5 Chemical Name Sodium Salt of [4-a-[4-(Diethylamino)-5'-Hydroxy-2',4'-Disulphonatobenzhydrylidene] Cyclohexa-2,5-Dien-1-Ylidene]Diethyl Ammonium Hydroxide Inner salt C.I. No 42051 C.I. Name Acid Blue - 3 FDA Status --- CAS No. 20262-76-4 EINECS No. 222-573-8 E.