In Rig Veda (around 2500 BC) it is mentioned about the worship of a "wooden deity" near the sea shore:" adoh yat daru plavate sindhohpare apurusham" meaning "that log of wood being washed by the sea is beyond the scope of metabolism". Initially parameswara was used which was subsequently changed to Purusottama and Jagannath. Some even say that the deity is older than the Vedas. Adi Sankaracharya (788-820 AD),however,saw the deity of Jagannath only on the Ratnavedi (the seat of gems).
Some, as stated above, observe that the deities have the simplicity and crudeness of folk sculpture and ascribe to tribal origin.The forms of Purusottama, Balabhadra and Subhadra are significantly different from the traditional shape of Kondhs, Gonds and Shabaras who worship Buddadeo(ancestors), Linga(Phallus) and Jangha(thigh).
The main deities of Jagannath temple at Puriare all made of wood taken from the "neem tree" (Melia Azadirachta Indica).The height of deities is between 2.5 to 3 meters.when touched the deities give a soft feeling instead of hardness of wood. This is due to the layers of pure silk warpped on the core wooden body.
The colours of Jagannath, Balabhadra and Subhadra are black, hite and yellow respectively. Social anthropologists interpret these colours to represent the three races of mankind viz. Negroids, Europeans and Mongoloiads. In the empirical language of physics black is the most ideal absorber of radiation, white a good reflector and the yellow one of the unadulterated primary colours. However, none knows why these earless, legless, tribal forms with oversized heads beckon to people to keep the traditions go!While the eyes of Jaganath are regular circles, the eyes of Subhadra and Balabhadra are oval. The head of Balabhadra is scalloped with a semi-circular lobe indicating a hood of a serpentSubhadra's head a tiara and Jagannath a straight line.
Different meanings have been attributed to the deities by various sects and schools of thought which may be classified in a nonexhaustive manner only:
The three deities have Vastra Shringar (dress regimen) too.Jagannath is dressed with clothes of prescribed colours viz. Sunday (red), Monday (white with black border),Tuesday (five assorted colours), wednesday (blue), Thursday (yellow), Friday (white), Saturday (black).As per lunar cycle deities are dressed up differently out of which 21 have historical significance viz. certain robes were introduced by none other than Chaitanya, Ganapatti Bhatta, Vallabhacharya, Ramanujaacharya and others in different centuries.