Green S food colouring molecule. Molecular model of Green S, an organic compound used as colouring in foods such as mint sauce, tinned peas and sweets. Green S, also known as E142, is very commonly used in the UK, but is banned in the USA, Canada, Japan and Norway. There are concerns over this food colouring being linked to allergic reactions, hyperactivity and temper tantrums in children. Research has shown that behaviour problems increase with higher additive levels in food, so parents have been advised not to give children foods containing these additives. Atoms are colour-coded: hydrogen (gold), carbon (green), nitrogen (dark blue), sulphur (yellow) and oxygen (red).