Festival of colours, holi is celebrated in many parts of India. This word is derived from the demon ruler Hiranyakashyap's sister, 'Holika.' It says that Lord Vishnu blessed Hiranyakashyap that he won't get killed by any animal or human being. So, he wanted the people to worship him rather than any God, due to which his own son 'Prahalad' worshipped Lord Vishnu inspite of knowing the unusual wish of his father.
Hiranyakashyap in rage of anger attempted many times to kill Prahalad but failed miserably. He tried to poisoned his son but poison became nectar, ordered wild elephants to kill him but Prahalad remained unharmed. Also the brutal father put his son in a room full of snakes and again under the blessing of Lord Vishnu, victim remained uninjured. Then, Hiranyakashyap took help of his demon sister Holika.
Holika made Prahalad sit on fire and protected herself with a blanket. But blanket flew away and Holika burnt into ashes where Prahalad came out of the fire unharmed. Next day, Prahalad went to the place where that burning incident took place and threw ashes of Holika in the air. Hence, we make holi by throwing colours on each other
After all of this Lord Vishnu arrived on the earth in disguise of half lion and half
and killed the villian, Hiranyakashyap.