The festival of Holi is celebrated because of a story in the old Hindu religion. In Vaishnavism, Hiranyakashipu is the great king of demons, and he had been granted a boon by Brahma, which made it almost impossible for him to be killed.
The boon was due to his long penance, after which he had demanded that he not be killed “during day or night; inside the home or outside, not on earth or in the sky; neither by a man nor an animal; neither by astra nor by shastra”.