Color plays a critical role in our world and in our everyday lives. Color is how we express ourselves, how we communicate with one another – how we know whether to stop or go at a traffic light! Color can influence our actions, and trigger emotional reactions. We take it for granted, but color… well, it colors our world!

The study of color, also known as chromatics, is a fascinating field, and without it, we wouldn’t know nearly as much as we do about rainbows! Sure, chromatics are about studying color, but it’s really all about light and the interactions light has with matter.

Where to begin? Any discussion of chromatics must begin with an examination of light itself!

What is Light?

Light is a form of energy that is transmitted via waves of radiation. Those waves have a distinct wavelength and a frequency. The wavelength, or the distance between crests of the ‘waves’ of light, and the frequency, or the number of waves that pass through a specific point per second, determine where the light falls on the electromagnetic spectrum (e.g., visible light, ultraviolet light, etc.). The other big difference between a wave of light and a wave in the ocean? Light doesn’t need water or air to travel; light is transmitted through a vacuum!

That said, when light hits particles of matter, that matter can change the way light behaves, and therefore, the way we observe it with the human eye. For example, have you ever paid attention to the way a straw looks when you drop it in a glass of water? The straw looks bent, right? That’s because the speed of light is slower in water than it is when passing through air. That difference in speed prompts the light to bend. This phenomenon is known as refraction.

Now that we’ve reviewed light and refraction, let’s dig into the nature of color and how it relates to light and refraction.

The Basics of Color Theory

How do we categorize and define the colors that we perceive? It’s a heady question, but one that deserves a little discussion.

The categories of color are associated with objects through the wavelength of the light that is reflected from them. This reflection is governed by the object's physical properties such as light absorption and emission spectra; in other words, whether it’s the desk in front of you or the images Made a few changes.on your computer screen right now, there are physical properties at play when it comes to seeing the color you’re seeing… at this very moment!

Let’s break down some of the basics of color theory:

  • Primary Colors in Light: Red, Blue and Green

    Primary colors are the three colors that cannot be mixed or formed by any combination of other colors; all other colors are derived from these three colors.

    Primary colors Model
  • Secondary Colors: Yellow, Magenta and Cyan

    Secondary colors are formed by mixing the three primary colors, and are essential to basic studies of color.

    Secondary colors Model
  • Tertiary Colors: Combinations of primary and secondary colours. There are six tertiary colors; red-orange, yellow-orange, yellow-green, blue-green, blue-violet, and red-violet.

    These are the colors formed by combining a primary with a secondary color.

So, What Causes Color?

The “cause” of color is complicated, and are both chemical and physical in origin. In general, the chemical origins of color are connected to the interaction of light with electrons to produce transitions in energy states. The physical origins are connected to light waves interacting with matter. Refraction is an example of a physical origin of color.

As we touched on earlier, light is just one part of a broader electromagnetic spectrum that includes visible light and ultraviolet light, but also radio waves, microwaves, infrared radiation, X-rays, gamma rays, and cosmic rays. It’s in the realm visible light where color lives.

The retina in your eye contains structures called rods and cones. Visible light is the part of the electromagnetic spectrum that is sufficiently energetic to cause chemical reactions in the rods and cones of your eye – without causing permanent changes or damage.

Each color of the visible light spectrum is associated with a specific frequency range. That is why each color of the rainbow – red, orange, yellow, green, blue, indigo, violet – correspond to a frequency range.

Believe it or not, color isn’t an intrinsic characteristic of an object in the same way its shape or its mass is; color is actually the result of light interacting with the object and then that light entering the rods and cones of the eye!

The Connection Between Chromatics and Rainbows

Now, let’s draw a connection between our color study and our favorite natural phenomenon – rainbows! In a sense, a rainbow is the perfect expression of the visible light spectrum. While rainbows can appear in various instances – whether your looking at the back of a compact disk, glancing at an oil slick across a puddle of water, or wearing a pair of diffraction glasses – let’s break down the appearance of a true rainbow.

First, understand that a rainbow is not an object, but really an optical phenomenon. Rainbows typically appear after a rain shower, when water drops are still floating in the air and the sun comes back out.

The sunlight shines through those water droplets floating in the air and refracts off of the inside of the droplet. This refraction process separates the light into its individual wavelengths – which, as you probably know by now, creates the distinctive band of colors!

When the light exits the water drop, the result from someone watching on the ground is a magnificent arc of color!

Continue Your Study of Color

At Rainbow Symphony, we offer a wide selection of light and color products specifically designed to aid in the study of color, light, chromatics, and – of course – rainbows! Explore our selection of educational products, including diffraction grating slides, diffraction grating glasses, color paddles, spectrum tubes, and so much more!

If you have any questions about our products, or would like to inquire about ordering in bulk or customization options, can call us toll free at 1-800-821-5122, or simply shoot us a message at