Why do ghosts wear white dresses?

Answer 1

Ghosts (female, specifically, of course) wear white dresses for many reasons. The first is that White has long been connected with death- the white light at the end of the tunnel, etc. In Western culture Black is associated with death because of the mourning clothes people wore and White is saved for happy events. In Eastern cultures white is associated with death and black isn't really symbolic of anything. How this switch came to be is unclear, but is a recent development.

It's possible that wearing white to a funeral was taboo because it was putting the wearer at risk of death, almost like you were expected to try to fight the prescence of death- probably done by wearing the opposite of white (black). They probably thought that with one person dead and the After so near, you'resusceptible to dying/spirits as well.

White is pure, and white is simple. It's technically not even a color. But ghosts are pure forms, and without the complications of the body, so it makes sense. White embodies spiritual things, and so maybe white is a default for ghosts. It's like a blank canvas for them, it's an emptiness and so it doesn't distract from who the spirit is. The dress can be explained as well. Dresses are really simple clothes, and just swirling light could be mistaken for a dress, even if they are wearing a white dress.

A lot of people believe that ghosts wear what they died in, but this may just be a matter of preference. It could just be that they have an attachment to the clothes or are unwilling to let go of the life they've left; and wearing white is the ghost "not caring", in a way. Indifference. Once again, going back to that default. What color the ghost is wearing is probably symbolic of their disposition. It's all choice.