High Quality Content by WIKIPEDIA articles! Ponceau 4R (also known as C.I. 16255 , Cochineal Red A, C.I. Acid Red 18, Brilliant Scarlet 3R, Brilliant Scarlet 4R, New Coccine) , SX purple) is a synthetic colourant that may be used as a food colouring. It is denoted by E Number E124. Its chemical name is 1-(4-sulpho-1-napthylazo)- 2-napthol- 6,8-disulphonic acid, trisodium salt.