In China, traditionally, white was the symbol of West and Metal, one of the main five colors.
In Chinese, Vietnamese, Korean, and Japanese tradition, white is the color of mourning and death.
In Indian tradition, white is also the color of purity and sacredness. It is also used for depicting Peace and Purity. However it is also the color of mourning. People wear white after death of any of their family members.
A white flag is an international sign of either surrender, or truce, that is, it is a sign of peaceful intent, typically at time of war.
White is the traditional color of bridal dress in both western (European) and Japanese weddings. In Western weddings, a white dress is thought to be symbolic of purity (the bride has not engaged in pre-marital sex). This is also said to be the symbolism of the veil. In Japanese weddings, white is to symbolize the "death" of their former family and their introduction into their new family.
In many RPG games, the White Mage class resembles purity