The Shanti Parva book of the Mahabharata describes the discourse given by the four Kumaras to the demon king Vritra and his guru - the sage Shukra. The king and his guru worship the Kumaras and then Shukra asks them to describe the greatness of Vishnu. Sanat-kumara starts with describing Vishnu as the creator and destroyer of all beings. He equates Vishnu's body parts with parts of the universe and the elements, for example the earth is Vishnu's feet and water is his tongue. All gods are describes as being Vishnu. Then Sanatkumara categorizes all beings into six colours depending upon the proportion of the three gunas: Sattva (pure), Rajas (dim) and Tamas (dark). From the lowest to the foremost beings, the colours are dark (Tamas is high, Rajas is mid, Sattva is low), tawny (Tamas is high, Sattva is mid, Rajas is low), blue (Rajas is high, Tamas is mid, Sattva is low), red (Rajas is high, Sattva is mid, Tamas is low), yellow (Sattva is high, Tamas is mid, Rajas is low) and white (Sattva is high, Rajas is mid, Tamas is low). (The Vishnu Purana gives non-living things, lower animals and birds, humans, Prajapatis, gods and the Kumaras are respective examples of the above colours.) Sanat-kumara elaborates further how a Jiva (living entity) journeys from dark to white in his various births, ultimately gaining moksha if he does good deeds, devotion and yoga.