How many colors are there?

Question

How many colors are there?

Answer 1

infinity.!

Answer 2

Color is how our eyes and brain interpret light. Our eyes can only see radiation with a wavelength of 380 nanometers to 740 nanometers. This is called the visible spectrum of light. Sir Issac Newton listed the pure spectral colors we see in light as red, orange, yellow, green, blue, indigo, and violet.

But "Roy G. Biv" isn't the only name in town when it comes to what colors exist. In 1790, researcher Thomas Young said the human eye sees only three colors -- red, blue, and yellow -- and every other color was just a combination of these primary colors. In 1878 Ewald Hering posited a theory of four unique hues of red, green, yellow, and blue, which, when mixed with white or black, represent all the possible colors humans can process. Useful knowledge for painters and printers perhaps, but it doesn't quite answer your question.

The problem is that nobody really knows exactly how many colors the human eye can see. The closest researchers can estimate is millions and millions. Scientific experiments have shown that humans can discriminate between very subtle differences in color, and estimates of the number of colors we can see range as high as 10 million.

Of course, every person's eyes perceive color a bit differently, and every culture has its own names for colors so coming up with an exact number may not be possible.