Where is the geological formation called the Seven Coloured Earths located?

The Seven Coloured Earths is a relatively small area of sand dunes comprising sand of seven distinct colours: red, brown, violet, green, blue, purple and yellow. Since the sands spontaneously settle in different layers, the dunes acquire a surrealistic, striped colouring. Another interesting feature is that the dunes seemingly never erode, in spite of Mauritius' torrential tropical rains.