Purple is a color that has captivated people for centuries. Associated with royalty, spirituality, and creativity, purple has a rich and intriguing history. But where does this color come from? The answer lies in the mixing of two primary colors – blue and red. When blue and red light are combined, the resulting color that our eyes perceive is purple. In this article, we will explore the science behind how mixing blue and red makes purple, look at the different shades of purple, and understand why purple has been prized for so long.
The Color Spectrum
To understand how purple is made, we first need to understand how color works. The colors we see are part of the visible light spectrum. This spectrum is part of the electromagnetic radiation given off by the sun. The full spectrum of electromagnetic radiation includes radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays.
Visible light is just a small segment of the full spectrum that our eyes can detect. Sir Isaac Newton discovered that when white light passes through a prism, it separates into the colors of the rainbow because each wavelength bends slightly differently. The visible light spectrum ranges from violet and blue light with short wavelengths, to green and yellow light with medium wavelengths, to orange and red light with longer wavelengths.
Primary and Secondary Colors
There are three primary colors that can be combined to create all other colors – red, green and blue. In the RGB (red, green, blue) color model, varying intensities of these three colors can produce millions of color combinations. For example, red and green light combined together make yellow.
When it comes to mixing pigments (paints and dyes) rather than light, the primary colors are red, blue and yellow. The secondary colors are created by mixing two primaries. Red and blue make violet or purple. Blue and yellow make green. Red and yellow make orange.
So in both the RGB model and with pigments, combining blue and red results in purple.
How Blue and Red Make Purple
Specifically, violet light has wavelengths of around 380-450 nanometers. Blue light is around 450-495 nm. Red light is around 620-750 nm. When blue and red wavelengths are emitted together, our eyes receive both ranges of wavelengths. But rather than detecting them as separate blue and red colors, our visual cortex perceives the combined wavelengths as purple.
This can be demonstrated with red and blue paints or dyes. When red and blue pigments are mixed, the resulting purple color reflects both the long red wavelengths and short blue wavelengths to our eyes at the same time. Rather than seeing distinct red particles and blue particles, we see the two blended together into purple.
Similarly, blue and red light combined makes the color between blue and red on the visible spectrum – violet or purple. Computer and TV screens take advantage of this by combining different intensities of red, blue and green light to display a wide range of colors. Purple is made by having more blue light than red light emitted by the pixels.
So while purple does not have its own specific wavelength, it arises as a perceptual effect thanks to our vision combining the wavelengths of blue and red when they occur together.
Shades of Purple
There are a wide variety of shades of purple that can be made by altering the proportions of blue and red. Here are some of the most common purple shades:
| Purple Shade | Description |
|---|---|
| Violet | More blue, less red – located at the end of the visible spectrum next to blue. |
| Purple | Balanced mix of blue and red. |
| Mauve | Somewhat more red than blue. |
| Fuchsia | Much more red, less blue. |
| Amethyst | Purple with a grayish tone, named after the purple version of quartz. |
As you add more red, the purple gets warmer, going from violet to fuchsia. Adding more blue results in cooler purples like lavender. You can make rich, deep purples by using dark violet mixed with dark crimson red. Light pastel purples contain more white.
So with paints, dyes or light, purple can be tuned to precisely the right hue by changing the intensity and proportions of the blue and red components.
History and Significance of Purple
One of the key reasons purple has been so prized throughout history is because it was extremely difficult to produce purple dyes for fabrics. The most famous purple in the ancient world was Tyrian or Royal Purple. This was made from secretions of a rare Mediterranean sea snail called Murex. Thousands of snails had to be gathered and processed to yield just a small amount of purple dye. As a result, purple cloth became associated with royalty and high status.
In the 19th century, chemists finally discovered easier ways to synthetically create purple dyes using coal tar derivatives. This made purple fabrics more affordable and expanded its use.
Besides status, purple is also tied to spirituality and mysticism. It is traditionally associated with wisdom, dignity, independence, creativity, mystery and magic. With its union of fiery red and calm blue, purple is seen as combining the vitality of red with the serenity of blue. This dual nature is what gives purple its rich symbolic meaning.
So while mixing blue and red to make purple is a straightforward physics and perception phenomenon, the color purple has taken on cultural meaning far beyond the component colors. The synthesis of blue and red in purple represents the synthesis of opposing elements in nature and human experience. This synthesis is the essence of what has made purple stand out as a color with profound symbolic depth.
Conclusion
When blue and red wavelengths of light mix together, our eyes and brain perceive the combination as the distinct color purple. Using different proportions of blue and red pigments or dyes also results in a range of purple shades. While purple does not have its own unique wavelength, it arises as a fusion of the two primary colors in human visual perception. The mixing of these opposites gives purple its mystical, creative, and spiritual associations that have intrigued people for millennia. So the next time you see the color purple, think about how this singular color embodies the synthesis of blue calm and red excitement reflected in light itself.
