It is believed that the squirrel, which has been named Pete, somehow got stained with dye. Perhaps this happened in the school storage room, where old printers and cartridges are kept.
Witnesses note that the squirrel's purple coloration is unusually uniform. This may be explained by the fact that Pete licked his fur after chewing on one of the cartridges. Experts suggest that after the next spring molt, the animal will most likely become a normal gray squirrel.
By the way, the gray squirrel recently made it onto the list of non-native animals in the UK that the country's government intends to combat. Gray squirrels, introduced to the UK in the 19th century, are blamed for displacing the country's native red squirrels.