Here you get a good sense of the different colors of the geology.

https://www.mexicali-blue.com/uncoverin ... e-geology/ Joshua Tree National Park is a geological wonderland, boasting a variety of different rock types. The park contains granitic, monzogranite, and quartz monzonite rocks from the High Desert Complex, as well as sedimentary rocks from the White Tank Formation. Both igneous and sedimentary rocks can be found throughout the park. Granitic rocks, which are composed of quartz, feldspar, and mica, are the most abundant type of rock in the park. These rocks are gray in color and can be seen in the boulders and outcroppings throughout the park.

Monzogranite and quartz monzonite are also found in the park and are characterized by their light pink color. The sedimentary rocks in the park come in the form of sandstone, limestone, and shale, and can be found in the canyons and crevices, as well as in the White Tank Formation.