When i was young i learnt that the short curled hair of Buddha is a symbolic of our delusions mind which we need to overcome it to gain enlightenment.
Bambi, Here i found more information, it an open eyes for me.
The Lakkhana Sutta and several other suttas are devoted to the concept of the 32 Signs of a Great Man (mahapurisalakkhana), a rather strange idea introduced into Buddhism at a later period. One of these signs pertain to the hair.
The relevant passage reads ‘Uddhaggani lomani jatani nilani anjanavannani kundalavattani padakkhinavattaka jatan’ (D.II,17). Word for word this means –uddhaggani = turns around or upwards,
lomani = hair,
nilanianjanavannani = black in color similar to collyrium,
kundalavattani = curled,
and padakkhinavatta = turning to the right.
by Shravasti Dhammika
So according to the sutta, the Great Man’s hair was black and curled upwards and to the right. It was probably thought to curl the right because the right has been, in nearly all cultures, considered more auspicious. Being the color of collyrium is interesting. The Pali and Sanskrit word nila means black, blue or dark. Now collyrium as it is used in India, is made from the ash of fleabane, ghee and a few other ingredients and is a black greasy substance. In Mahayana sutras the nila gradually came to be understood as being blue. In the Gandhavyuha Sutra’s discussion on the signs of a Great Man it glosses nila as ‘the color of thevairocana jewel’ which is blue in color. This is why Tibetan Buddha statues have blue hair.
Anyway, when the first sculptors made Buddha statues they tried to depict at least some of the 32 signs. It is thought that the first Buddha statues were made in Gandhara under Greek influence, and in Mathura, in around the 1st/2nd centuries CE. Greek or Greek-influenced sculptors in Gandhara, perhaps more rooted in reality, depicted the Buddha’s hair naturalistically as, not exactly curling to the right, but waving to the right. The first Mathura-manafactured Buddhas show him with a single bun spiraling to the right, something like a Mr. Whippy ice cream. The Gandhara style never penetrated into India proper and eventually died out. The spiraling Mathura style eventually evolved into many spiraled curls and the Buddha’s hair has been depicted in that manner ever since.
by Shravasti Dhammika