The Sanskrit word varna means colour. From this it is evident that originally caste was concerned with colour. In the ancient India there were various racial groups, the dark aboriginal tribes, the sturdy Dravidian, yellow skinned Mongols and the forceful red complexion Aryan. In Mahabharata also the division of caste was based on colour. It is found when Bhrigu explains the theory of origin of varna to Bharadwaja holds only a few Bhramans were first created by the great Bhraman. Later on, the four classes are developed from it. The complexion or varna of the bhramana was white or sita, that of kstriya red lohita, that of vaisya yellow or ritakah and that of sudra black or asita.
The vedic conception regarding the origin of the varnas from the limb of the cosmic person also finds a place in the Mahabharata and the Manusmriti.
Purusha Sukta of the Rigveda is the first reference to the four classes where Bhramanas are said to be sprung from the mouth of the cosmic person, Kstriya from the man, from thighs Vaisya and the Sudra from his feet. The four castes of the society were represented in a symbolic way in order to maintain the organic character of the society. Bhramanas are originated from the mouth means they are instructor and teacher of mankind. The arms are the symbols of strength which possess the Kstriyas. The lower part of the body represents consumer of food, hence Vaisya provide food to the people by practising agriculture and trade and Sudra from the foot of the cosmic person symbolizes the servant, or to serve the other varnas as all other parts of the body is carried by foot.
It is clear from the above statement that Varnadharma at the initial stage was based on colour. It was the attitude of the ancient people to start their life with a narrow outlook. But in course of time they changed their outlook and developed a code of ethics applicable for all. Varnadharma which was based on colour are replaced by the deeds of the individual. It also avoided the heredity principle. A man is known by his deeds not of his family where he is born. For evidence, Viswamitra, a kstriya becoming a Bhraman by dint of his own effort is recorded in both epics. Parasurama a Brahmin who becomes a kstriya by profession. The Padma Purana tells us that Vaishistha who was the son of a courtesan (vesya putra). Vyasa who is considered to be the author of the Mahabharata born of a fisher women, and Parasara of a candala girl. There are several other instances recorded of change of Varnas, for example in the Matsya Purana, The Vayu Purana, and the Harivamsa.