Why do deserts often have brightly coloured rocks?

Desert landscapes often display bold colours because bare rock and exposed sediments are not hidden by plants or soil. In dry environments, iron-bearing minerals can oxidize and produce red, orange, and yellow tones, while other minerals create white, green, or purple layers. Wind and water remove loose material, exposing fresh rock surfaces and banded strata. Famous examples include the red sandstones of the American Southwest and multicoloured desert badlands.