Onam, which is an annual harvest festival of Kerala, has created a festive mood in God's own country. The festival is mainly celebrated by Malayalees around the world with traditional folk dances, artworks, etc,.
According to the Onam story and its popular myth, Lord Vishnu in his Vamana avtar sents King Mahabali to hell as the gods become jealous of his popularity. But grants him a boon that the king can visit his subjects once in a year. Thus, it is believed that Onam is celebrated as King Mahabali's visit to the place. It is the only festival in which both the winner and the defeater are worshipped.
The harvest festival brings many colours with it and thus celebrated in a grand way in Kerala. From 'Atham' to 'Thiruvonam', it is a celebration of ten days.
Check out the above slideshow of Onam Celebration and its different colours.