Why does Ayer's Rock change colors?

Answer 1

Ayers rock, more correctly known as Uluru, appears to changes colour at different times of day due to the sun. The different angles of morning sun and late afternoon sun reflect differently off the surface of the Rock, and interact with the different soil colours surrounding the Rock, to also alter its appearance from the brilliant orange-red of early morning to the deeper, dusky-red of later afternoon. On an overcast day, the Rock's colour is also more subdued, turning to a grey-brown colour. It is largely a matter of the atmospheric conditions, and how the moisture levels in the air and any clouds reflect the surrounding desert colours back onto Uluru.