You've seen our Original CMY cube online or in person, and now you're probably wondering how it works. This post will explain the science behind this colourful contraption! Stay tuned for a detailed explanation of each colour and what happens when they are combined.
What is subtractive colour mixing?
There are two important types of colour blending approaches, additive and subtractive. In the additive colour mixing approach, there is an addition of one wavelength of light into another. Whereas subtractive uses the opposite methodology, it eliminates the wavelength of the light from the white light2,3.
Subtractive colour mixing is also known as absorption colour mixing, it is the most commonly used technique in the printing industry, where only four colours are used namely Cyan, Magenta, Yellow, and Black4.
How does the CMY cube work?
The CMY cube has six sides and the colours used are cyan, magenta, and yellow only. With the light falling onto the cube, it changes colours and makes it an interesting object for everyone. When we look at the cube from each side, it shows one of the three primitive colours. On the other hand, whenever the angle through which the cube is viewed as it is tilted, and the other sides are visible the cube illuminates with new colours. It mainly occurs because the light is refracted in the cube changing the light’s wavelengths1.
Where is it used in the industry?
In the modern world, subtractive colour mixing is the most widely adopted procedure for colour fabrication. This technique plays a crucial role in the lives of consumers as this is the reason we see countless combinations of colours in the constructed environment around us. It is used in the printing of paper in the inkjet printers, oil painting, and textile sector5.
With the aid of different colours, we make printing more interesting and it not only impresses the viewer but also makes it convenient for them to differentiate between the information at hand. In the textile sector, it is used as a primary mixing technique in the process of heat transfer imprinting printers for printing patterns6.
What are the recent developments in the field?
RGB colours are widely used in computer graphics as well as photo and video editing software. But when it comes to printing RGB is converted to CMY because we mostly have to print on white paper where subtractive colour mixing is advantageous. In the recent development in subtractive colour mixing, to get most of the hues we often use CMYK where K is the Key or Black colour.
The addition of black reduces the gap between the theory and practical application of CMY. In theory, black colour is not needed as the colours are produced by subtracting Cyan, Magenta and Yellow from the white light. If all colours are subtracted in equal proportion from the white light, we get the perfect black colour as a result. While in reality when we subtract an equal number of colours from the white the result is not perfect black so we use black or key colour with CMY to get a perfect black output. black in CMYK also helps to create darker hues or shades of the colours7.
Why are new colours created when turning the cube?
The reason behind the creation of the different colours appearing on the cube is the angle of refraction of the cube as well as the light source. As the light gets refracted in the cube it changes its colour just like when the light is refracted onto a prism it is refracted and it is then separated in a wide range of colours with different wavelengths. Every colour has a different wavelength, so the light is refracted and the colour appears based on its corresponding wavelength3.
What is happening at the photon level inside the cube?
To understand the physical phenomenon happening inside the cube, we should be aware of the basic principle of light refraction and reflection. Moreover, how we see objects using the eye also plays a vital role in understanding the concept behind the CMY Cube. As we already discussed the cube sides are made up of 3 colours; Cyan, Magenta and Yellow. And we see objects with our eyes when light is reflected from the surface of that specific object. If there is no light in the room, we’ll not be able to see anything. Similarly, when the light is reflected from the sides of the cube, we see the colours (Cyan, Magenta and Yellow) on it.
When the cube is placed perpendicular to the direction of the viewer, there is no refraction of light in that case. As soon as we change the angle of the cube the refraction of light begins to take effect. In CMY colour space, we see colours because the white light is absorbed by colours and the subtracted result is visible to our eyes. The same happens in the CMY Cubes. White light passes through the cube and reaches our eyes from different sides of the cube, on its way the white light loses certain wavelengths and we see the colours on the cube which are the results of subtraction1,2,3.
How the environment in which the cube is viewed affects the experience?
CMY Cube is a great physics tool to teach children and adults about the magic of colours, light, the electromagnetic spectrum, and the properties of waves. For the best visual experience the cube should be viewed in an environment with an abundance of pure white light such as a lightbox or a bright white room, as subtractive colour mixing is a result of the absorption of certain colours from white light. For instance, we see a red colour when magenta and yellow are subtracted from white light and so on with the other visible colours. With an abundance of white light the colours obtained will be perfect but if there is another colour instead of white, you’ll not be able to see all possible colours because we can’t subtract a colour which is not already present in the original light source.
What are similar effects that we see in our everyday lives?
We see effects of refraction and reflection almost everywhere in our daily life and colour mixing techniques are also widely employed in objects of daily use. In LED smart bulbs, RGB colour mixing is used as we have light-emitting diodes of 3 colours; red, green and blue. The mixing of these primary colours results in a wide range of colours. These lights are used in house interior and the film industry to create different hues of background lighting. The Rainbow is a natural phenomenon where we can witness the refraction and reflection of light which results in the spectacular representation of colour. If you’re an artist or love to paint on the canvas using watercolours, then colour mixing techniques are of utmost importance for your workflow and CMY cubes can help to understand that which colours can be mixed to get a certain shade of colour.
Bring colour and light into your world with the CMY Cube
With its mesmerising display of spectral light, the CMY Cube is sure to captivate your senses and leave you longing for more. If you're looking for a toy that will stimulate your imagination and expand your understanding of the universe, look no further than this magnificent creation. Shop now and experience the beauty of science first-hand!
 Waldman, Gary, Introduction to Light, The Physics of Light, Vision and Color, Prentice-Hall, 1983.
 https://www.printplace.com › reasons-for-cmyk-printing
 Eggleston, P. (2001). The future of color printing: Beyond CMYK. 16. 28-29+34.
 Williamson, S J and Cummins, H Z, Light and Color in Nature and Art, Wiley 1983.