Have you ever mixed paint and ended up with brown instead of purple? Or wondered how TVs make color using just red, green, and blue? If so, you’re not alone. The difference between additive and subtractive color can be confusing, but it’s also incredibly fascinating. And best of all, it can be explored hands-on with tools like the CMY Cube.
Understanding this key concept in color theory unlocks a whole new way of seeing how the world is built on light, pigment, and perception. Whether you’re a student, a teacher, or just curious about the science of color, this guide will show you exactly how these two systems work, and why your CMY Cube is more than just a pretty object.

What Is Additive Color?
Additive color is how light mixes. It’s called “additive” because when you add more light, you get brighter and lighter results. This system uses three primary colors: Red, Green, and Blue , also known as RGB.
You’ll see additive color mixing in action anywhere light is the source. That includes:
Television and phone screens
Projectors
Stage lighting
LED displays
When red, green, and blue lights overlap in equal intensity, they create white light . This is the opposite of what happens with paint. With additive color, more equals brighter.
Here’s how the combinations break down:
Red + Green = Yellow
Red + Blue = Magenta
Green + Blue = Cyan
Red + Green + Blue = White
It might sound strange at first, but your phone’s display is creating every photo and video you see using just these three colored light sources.
What Is Subtractive Color?
Subtractive color is how pigment or filters mix. It’s called “subtractive” because each pigment removes certain wavelengths of light and reflects the rest. The more pigment you add, the darker the result.
The primary colors of subtractive mixing are Cyan, Magenta, and Yellow or CMY. These are the colors used in printing, painting, and physical filters like CMY Cubes.
Each pigment absorbs (or subtracts) a portion of white light:
Cyan absorbs red
Magenta absorbs green
Yellow absorbs blue
When you mix them:
Cyan + Magenta = Blue
Cyan + Yellow = Green
Magenta + Yellow = Red
Cyan + Magenta + Yellow = Black or near-black
This is why when you mix all your paints together, you get something murky instead of bright. You’re subtracting more and more light until barely any is left.

CMY Cubes: Subtractive Color in Action
The CMY Cube is a hands-on way to explore subtractive color mixing. Unlike traditional paint or ink, it’s made from transparent colored filters layered in a cube. As light passes through these layers, it gets filtered or subtracted, revealing different colors depending on the angle.
Try this:
If you already have a CMY Cube, hold it up to a light source and look through it. Rotate it slowly. Watch as the colors shift from cyan to green to red to purple.
What you’re seeing is subtractive mixing in real time. The cube layers subtract certain wavelengths from the light. As the filters overlap, new colors emerge.
This is a visual, sensory-rich way to teach and understand subtractive color theory. You’re not just reading about it. You’re holding it, turning it, and discovering how it works with your own eyes.
Comparing the Two: Additive vs Subtractive
Additive Color (RGB): Uses light
More light = brighter colors
Primary colors = Red, Green, Blue
Mix all = White
Used in screens, LEDs, projectors
Subtractive Color (CMY): Uses pigment or filters
More pigment = darker colors
Primary colors = Cyan, Magenta, Yellow
Mix all = Black or dark brown
Used in printing, paint and CMY Cubes!
So when your printer runs low on ink and can’t print rich blacks, it’s likely missing one of the CMY elements. And when your screen shows vivid color, it’s blending RGB light directly into your eyes. Both systems are accurate, just applied in different ways. Understanding both helps unlock the mystery behind how we see color in the world around us.

Science Experiment: Exploring Both Systems
Here’s a great activity to illustrate the difference using simple materials and your CMY Cube.
Materials
A CMY Cube
Red, green, and blue flashlights or phone screens
White paper
Paints or markers in cyan, magenta, and yellow
Activity 1: Additive Mixing (RGB)
Shine red, green, and blue flashlights onto a white surface. Try overlapping the beams. Watch the color combinations appear.
Try to predict what two colors will create. For example, red and green make yellow light. Red and blue make magenta.
Activity 2: Subtractive Mixing (CMY)
Take your CMY Cube and hold it over white paper in a well-lit space. Rotate the cube and observe the color transitions.
Now use the CMY paints to mix pigments directly on the paper. Try magenta and yellow to make red, or cyan and yellow to make green.
Use both methods to help learners understand that light and pigment follow different rules, but both reflect how color works in nature and technology.
Real-Life Connections
Understanding additive and subtractive color has practical use in:
Graphic design
Photography and film
Printing and publishing
Stage lighting
Art and fashion
Even makeup and hair dye
And of course, this knowledge fuels creative exploration with CMY Cubes. Once you grasp how color behaves in different forms, you can start to manipulate it, play with it, and teach it in an entirely new way.
Final Thoughts
Additive and subtractive color theory might seem complex, but with a CMY Cube in hand, it becomes something you can see, touch, and explore. Whether you’re mixing paint or programming pixels, understanding the difference between RGB and CMY is essential for creative thinkers, artists, scientists, and students.
So next time you adjust your screen brightness or layer paints in a notebook, take a moment to think about how light and pigment are shaping your view of the world. And if you have a CMY Cube nearby, use it as your guide to uncover the colorful science that surrounds you.