Tyres colour is black due to the proportion of carbon mixed in it during the vulcanization of the rubber, to make the tyre shear resistant. Without vulcanization tyres won't be able to bear the friction heat and stress of the road. Thus carbon is responsible for giving tyres the prominent black colour. Adding of carbon prevents tyres from rapidly deteriorating because when ozone combines with the ultraviolet light from the sun. It attacks the polymer of the tyre.