In preservation of food . . . . . . . . PPM of colour is permitted.

Food preservation can be defined as the process of treating and handling food in such a way as to stop or greatly slow down spoilage and prevent foodborne illness while maintaining nutritional value, texture and flavour.
In food preservation colour is added to make food more attractive, appealing, appetizing, and informative. In preservation of food 200 ppm of colour is permitted.