Most "white elephants" seen in photos, ilike the one above, are found in Etosha NAtional Park, in NAmibia, where, owing to the colour of the dust, they take on a whitish colour from the environment. It is just dust from the environment.
The white Elephants are known as albino Elephants, they are not as much as the dark colored Elephants. The birth ratio of white Elephants is 1 in 10,000 births.
As at 2010, Myanmar had about 9 white Elephants which is used as a symbol of power and good fortune. In Thailand, they are considered scared and a symbol of royal power.
It would be a bit challenging to give the exact number of white Elephants in the world because they are not well documented but we can give an estimate from the total number of Elephants in the world. Since the birth of white Elephant occurs in 1 in 10,000 birth and they are less than 7 hundred Elephants in the world, we can estimate that they are less than 70 white Elephants in the world.