Visible Color Spectrum Wheel

All of us are familiar with the color wheel which we have seen in a painting class or while studying about light wavelength in physics. A color wheel is nothing but a visual chart of all visible colors that are arranged in a certain way. This is done so that we can understand the relationship between colors and which colors are complimentary or contrasting. This comes in useful in interior decoration, garment designing and other such fields where harmony of colors is vital. The first color wheel was invented by Sir Isaac Newton in 1706, when he passed a beam of sunlight through a prism and it produced the colors of the visible spectrum.

So the next question is what is the visible spectrum? Light as we know is an electromagnetic wave which is visible to our eyes. There are other electromagnetic waves like radio waves, ultraviolet waves, infra-rays and microwaves which are not visible to the human eye. Each color that we see actually has a different wavelength and that is why we able to discern them as different color. Sunlight or white light is composed of these different wavelengths of light and we can see them as different colors when it is passed through a prism. This is known as the wavelength of visible light spectrum.

When a ray of light falls on a colored object, most of the light is absorbed and only one color is reflected. For example a blue object, absorbs nearly the full spectrum of light, reflecting the color blue only. Thus, when we see blue or for that matter any colored object, it means that that color is being reflected and all the other colors of the electromagnetic spectrum of light is absorbed.

Color Wheel and Color Spectrum

The wavelength of visible light is between 390 to 750 nm, which is visible to the naked eye in the form of light. In a visible color spectrum wheel, all the visible colors are painted on a circle or wheel. The three primary colors which are red, yellow and blue are placed around the three points of an equilateral triangle of the color wheel. These primary colors are also known as pure colors as they cannot be made by mixing any other colors.

The secondary colors, green, orange and violet are then placed in between the primary colors at equal distances. The secondary colors are made by mixing two primary colors in equal proportion. Orange is made by mixing red with yellow, violet is made by mixing red with blue and green is made by mixing blue with yellow. The six tertiary colors which are red-orange, red-violet, yellow-green, yellow-orange, blue-green and blue-violet are made by mixing each primary colors with the adjacent secondary color in the color wheel. For example red-orange is made by mixing primary color red with secondary color orange. Red orange is then placed in between red and orange in the color wheel. All the other five tertiary colors are placed in the color wheel in the same way, i.e., in between the primary and secondary colors from which it is made.

This 12 colors form the basis of the visible color spectrum chart or wheel. But in reality, there are many more colors, shades and hues and not simply 12. Many color wheels show more gradation of colors and has 24 colors on the color wheel. In theory, all colors can be made by mixing the primary colors with secondary and tertiary colors and the number of colors will be infinite. But in reality, it is very difficult for paint companies to come up with so many variations.

One of the most interesting fact about a visible color spectrum wheel is that if the color wheel is spinning rapidly, our eye can see the color white, which is not even in the color wheel. When the color wheel spins rapidly, the colors merge into each other very fast and our brain is not able to distinguish between the different individual colors. So the reflection of the colors are blended and we see white light or white color. When all the light of the visible spectrum is absorbed, we see the color black. The color wheel is invaluable for artists as well as physicists who study the interaction of colors.