why dress of ghost is figured as white?

well first of all I think its due to many reasons 1.They are more visible in dark and more scary. 2.God does not bother to die the clothes he gives to spirits. 3.It has become a trademark of sorts over the years. 4.Female ghosts look more beautiful in white. 5.when we die we are covered mostly in with white cloth-no one has changed that system. 6.Since when we are in spirit form we wont be able to block anyone's view while passing through windows or rooms.we will reflect back all the light 7.our clothes gather less dirt as we are floating hence can wear whites easily. I think seven is enough.Thats a lucky number too.

As if they can pass through the wall or mirror. As if the are weightless.. that's it.