Don't adjust your color settings. The Grand Prismatic Spring in Yellowstone National Park really is this colorful. The varying hues in this hot spring come from all of the different organisms living in it. No wonder Yellowstone became the first national park way back in 1872, and why we definitely include it as one of THE MOST colorful spots in the US. Tap our bio link to see other places that ROY G BIV would absolutely love to visit.