@beverley365 As I understand it, it is part of the tracking process. So if there is an outbreak of a disease, the numbers on the tags can track the sheep back to where it came from and everywhere it has been in between and any other sheep it has been in contact with. The paint is sprayed onto sheep after they have been inseminated. Each colour corresponds to the ram who is the "father" and a second colour is sprayed on after a scan which lets the farmer know how many lambs to expect from each sheep (usually a maximum of 3 different colours for 1, 2 or 3 lambs)
