The term “vermilion cliffs” has too many definitions. As used here, I refer to the Vermilion Cliffs National Monument. (Unfortunately, I was not able to visit the areas within it known as The Coyote Buttes or The Wave or most of the equally famous Paria Canyon, so you’re getting a subset here.) I was impressed by the intensity of colors in the rocks.
The first pictures are from Paria Canyon, which is a famous 38-mile backpacking route, generally considered to be one of the premiere backpacking routes in the southwest. I didn’t have a permit for the entire trip, so I hiked the bottom 8 miles. It blew me away. Never have I seen such vibrant colors in a landscape (unless it would be Bryce Canyon). The photos below don’t quite show all of the brilliance, but you’ll get the idea.