The wavelength of light (related to frequency and energy) determines the perceived color. The range of these different colors is listed in the table below. Some sources dramatically change these ranges, and when they mix with each other, their boundaries are somewhat similar. The edges of the visible spectrum mix with the levels of ultraviolet and infrared radiation. Most of the light we interact with is in the form of white light, which contains many or all of these wavelength ranges. The white light flashing through a prism bends the wavelength at slightly different angles due to the refraction of light. Therefore, the resulting light splits in the visible spectrum. That’s why rainbows are created. Water particles carried in the air act as refractive media. Red, orange, yellow, green, blue, indigo (blue/purple border) and purple mnemonic “Roy G. Biv” can remember the order of wavelength. If you look closely at the rainbow or spectrum, you will find that the blue color is also quite obvious between green and blue. It is noteworthy that most people cannot distinguish indigo from purple, so many color charts completely omit it. By using special light sources, refractors and filters, narrow bands with a wavelength of about 10 nanometers can be obtained, which is considered monochromatic light. Lasers are special because they are the narrowest monochrome light source we can get. The color consisting of a single wavelength is called spectral color or pure color. Human eyes and brains can distinguish colors better than spectral colors. Purple and magenta are ways for the brain to bridge the gap between red and purple. Unsaturated colors, such as pink and water, can also be distinguished, as well as brown and brown. However, some animals have different visible ranges, usually extending to infrared (wavelength greater than 700 nanometers) or ultraviolet (wavelength less than 380 nanometers). For example, bees can see ultraviolet light, which flowers use to attract pollinators. Birds can also see ultraviolet light, and spots can be seen in black (ultraviolet) light. In humans, the distance between red and purple is different. Most animals that can see ultraviolet rays can’t see infrared rays.