There are nearly an infinite number of colors, according to the Chester F. Carlson Center for Imaging Science at the Rochester Institute of Technology. However, not all of them are distinguishable by the human eye.
Mathematically, when multiplying the nearly 10 million distinguishable colors with the thousands of outside forces acting on the brain's perception of those colors — such as light, surfaces and viewing conditions — psychophysicists have determined the number of potential colors and combinations to be almost endless. Each person's perception of those colors will also vary due to the large variety of outside factors and ever-changing context.