Yellowstone is home to several (almost 1/2 of the entire Earth's) geyser basins; the most famous of these is the Old Faithful Geyser basin home of many different geysers.
The Anemone Geyser erupts 4 to 5 times an hour and is a typical fountain type geyser. The eruptions spurt about 5-6 feet in the air with the most memorable part of this geyser being how it ends. It ends with a giant flushing sound just like a 300 gallon toilet. It is simply a great sound.
The colors are the result of various bacteria, known as extremophiles, with each color representing a specific temperature.