Why colouring agents added to medicine?

Answer 1

Pharmaceuticals are coded so that they can be identified easier. They are identified by form, colour, shape, and text. For example if you found a blue pill with "xanax 1.0" written on it you could tell the dose by the colour.

Answer 2

Its because some people take 2-20 tablets a day, these need to be identified from each other. Some may be dissoluble some may have to be taken at night. Its best to know this, you wouldn't like to get them mixed up would you. And it makes them slide down your throat if you have a throat infection.