One of the great things about hiking in the Grand Canyon is viewing the huge variety of colors. The Coconino sandstone is yellowish-tan, the Hermit shale is gray, other shales have a greenish tint, the Muav has a purple hue, the Tapeats is a rich brown color, and the Redwall Limestone fools us with its white color being washed over with red silt dissolved from the Supai sandstone.
This panorama is low in the Vishnu schist. This single igneous layer, alone, has all the colors described in all the sedimentary layers above it. Here we see black, pink, white, and yellow, and many shades in between. All of the rocks shown in this panorama are igneous Vishnu schist and granitic intrusions with just a bit of Tapeats peaking out high above at both ends of the canyon.
Another exciting phenomena of the erosion processes in the Grand Canyon are the polished sluices where the water and sand from flash floods or constant flows carve the rocks into strange, and sometimes beautiful shapes and forms. The Vishnu schist, and other associated igneous materials, take a particularly high polish and become quite slick for foot travel.
GCPano.org