麻豆约拍

Chemical reactions are used to produce different colours of dye to change the colour of a white football kit. Although we can now choose from a wide range of colours this hasn't always been the case and one type of yellow dye was once produced from cows' urine. An expert on dyes explains how chemists have discovered ways of making almost any colour from chemical reactions and we see the presenter make an orange dye from two colourless chemicals.