It doesn’t, it’s just the light reflecting on it at different times of the day.

my visit to Ayres Rock was during two of the 50 days rain they have each year. They tried to tell me I was privileged but seeing that in UK I get all the rain I want, I could not see the strength of their viewpoint. Another whinging Pom I suppose. Having said that the smell in the air was something to behold it was so pleasant and flowers were beginning to bud so there was some compensation for the disappointment