Physics Tutorial: Color Addition (2023)

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The Physics Classroom » Physics Tutorial » Light and Color » Color Addition

Light Waves and Color - Lesson 2 - Color and Vision

  • The Electromagnetic and Visible Spectra
  • Visible Light and the Eye's Response
  • Light Absorption, Reflection, and Transmission
  • Color Addition
  • Color Subtraction
  • Blue Skies and Red Sunsets
(Video) The Physics Classroom Color Addition

Color perception, like sound perception, is a complex subject involving the disciplines of psychology, physiology, biology, chemistry and physics. When you look at an object and perceive a distinct color, you are not necessarily seeing a single frequency of light. Consider for instance that you are looking at a shirt and it appears purple to your eye. In such an instance, there may be several frequencies of light striking your eye with varying degrees of intensity. Yet your eye-brain system interprets the frequencies that strike your eye and the shirt is decoded by your brain as being purple.

Primary Colors of Light

The subject of color perception can be simplified if we think in terms of primary colors of light. We have already learned that white is not a color at all, but rather the presence of all the frequencies of visible light. When we speak of white light, we are referring to ROYGBIV - the presence of the entire spectrum of visible light. But combining the range of frequencies in the visible light spectrum is not the only means of producing white light. White light can also be produced by combining only three distinct frequencies of light, provided that they are widely separated on the visible light spectrum. Any three colors (or frequencies) of light that produce white light when combined with the correct intensity are called primary colors of light. There are a variety of sets of primary colors. The most common set of primary colors is red (R), green (G) and blue (B). When red, green and blue light are mixed or added together with the proper intensity, white (W) light is obtained. This is often represented by the equation below:

R + G + B = W

In fact, the mixing together (or addition) of two or three of these three primary colors of light with varying degrees of intensity can produce a wide range of other colors. For this reason, many television sets and computer monitors produce the range of colors on the monitor by the use of red, green and blue light-emitting phosphors.

The addition of the primary colors of light can be demonstrated using a light box. The light box illuminates a screen with the three primary colors - red (R), green (G) and blue (B). The lights are often the shape of circles. The result of adding two primary colors of light is easily seen by viewing the overlap of the two or more circles of primary light. The different combinations of colors produced by red, green and blue are shown in the graphic below. (CAUTION: Because of the way that different monitors and different web browsers render the colors on the computer monitor, there may be slight variations from the intended colors.)

Physics Tutorial: Color Addition (2)

Color Addition Rules

These demonstrations with the color box illustrate that red light and green light add together to produce yellow (Y) light. Red light and blue light add together to produce magenta (M) light. Green light and blue light add together to produce cyan (C) light. And finally, red light and green light and blue light add together to produce white light. This is sometimes demonstrated by the following color equations and graphic:

(Video) conceptual physics Color mixing

R + G = Y
R + B = M
G + B = C
Physics Tutorial: Color Addition (3)

Yellow (Y), magenta (M) and cyan (C) are sometimes referred to as secondary colors of light since they can be produced by the addition of equal intensities of two primary colors of light. The addition of these three primary colors of light with varying degrees of intensity will result in the countless other colors that we are familiar (or unfamiliar) with.


On this page we've discussed adding red, green and blue light in equal intensities. What happens if they are added in unequal intensities? For instance, suppose you are on the stage lighting team for your school's theatre. Your task is to control the red, green and blue stage lights to produce various color effects for the upcoming show. Use the Color Addition widget below to adjust the strength of the red, green and blue lights relative to full strength. A 1.00 indcates that the light is on at full strength; a 0.00 means the light is off. (All numbers should range from 0.00 to 1.00.) Once adjusted, click the Mix 'Em Up button to find out the result of mixing red, green, and blue components at various strengths.

Complementary Colors of Light

Any two colors of light that when mixed together in equal intensities produce white are said to be complementary colors of each other. The complementary color of red light is cyan light. This is reasonable since cyan light is equivalent to a combination of blue and green light; and blue and green light when added to red light will produce white light. Thus, red light and cyan light (which is equivalent to blue + green light) represent a pair of complementary colors of light; they add together to produce white light. This is illustrated in the equation below:

R + C = R + (B + G) = White

Each primary color of light has a secondary color of light as its complement. The three pairs of complementary colors are listed below. The graphic at the right is extremely helpful in identifying complementary colors. Complementary colors are always located directly across from each other on the graphic. Note that cyan is located across from red, magenta across from green, and yellow across from blue.

Complementary Colors of Light
Red and Cyan

Green and Magenta

Blue and Yellow
Physics Tutorial: Color Addition (4)

The production of various colors of light by the mixing of the three primary colors of light is known as color addition. The color addition principles discussed on this page can be used to make predictions of the colors that would result when different colored lights are mixed. In the next part of Lesson 2, we will learn how to use the principles of color addition to determine why different objects look specific colors when illuminated with various colors of light.

(Video) Additive and Subtractive Color with Ray Diagrams, Chapter 16 Review

We Would Like to Suggest ...

Physics Tutorial: Color Addition (5)Sometimes it isn't enough to just read about it. You have to interact with it! And that's exactly what you do when you use one of The Physics Classroom's Interactives. We would like to suggest that you combine the reading of this page with the use of ourRGB Color Addition Interactive. The Interactive is found in the Physics Interactives section of our website and allows a learner to adjust the intensity of red, green, and blue spotlights shining upon a white surface and to observe the appearance. Explore the result of mixing R, G, and B lights in equal and unequal intensities.

Visit:RGB Color Addition Interactive

Check Your Understanding

1. Two lights are arranged above a white sheet of paper. When the lights are turned on they illuminate the entire sheet of paper (as seen in the diagram below). Each light bulb emits a primary color of light - red (R), green (G), and blue (B). Depending on which primary color of light is used, the paper will appear a different color. Express your understanding of color addition by determining the color that the sheet of paper will appear in the diagrams below.

Physics Tutorial: Color Addition (6)

See Answer

Physics Tutorial: Color Addition (7)

R + G ---> Yellow

R + B ---> Magenta

(Video) Color and Refraction

B + G ---> Cyan

2. Suppose that light from a magenta spotlight and light from a yellow spotlight are mixed together, will white light be produced? Explain.

See Answer

Physics Tutorial: Color Addition (8)

Answer: No

The magenta spotlight can be thought of as a combination of red and blue light in equal intensities and the yellow spotlight is equivalent to a combination of red and green light in equal intensities. Observe the double abundance of red. Combining the light from the magenta and yellow spotlights will produce a whitish-red color - that is, pink.


Next Section:

(Video) What Is Color? | Physics in Motion

  • Color Subtraction
  • Blue Skies and Red Sunsets

Jump To Next Lesson:

  • Anatomy of a Two-Point Source Interference Pattern


Physics Tutorial: Color Addition? ›

By convention, the three primary colors in additive mixing are red, green, and blue. In the absence of light of any color, the result is black.

What 3 colors are used for color addition? ›

By convention, the three primary colors in additive mixing are red, green, and blue. In the absence of light of any color, the result is black.

What is the addition color theory? ›

The additive color model describes how light produces color. The additive colors are red, green and blue, or RGB. Additive color starts with black and adds red, green and blue light to produce the visible spectrum of colors. As more color is added, the result is lighter.

How do colors form by addition? ›

Additive mixing of color takes place when two or more light beams with different colors are superimposed on a screen or directly on the retina of the observing eye. One example is theater stage illumination where several colored light projectors illuminate the same region.

How do you make colors flow? ›

Unify Colors with Trim. Painting all of the trim throughout the house the same shade of white is a simple way to create a sense of flow from room to room. White trim ensures that these spaces look connected and reinforces the effect with subliminal cues that make people feel anchored as they move through your house.

What are the 7 color theory? ›

Itten identified seven fundamental categories of contrast: hue, light-dark, cold-warm, complementary, analogous, saturation, and extension. The color star modeled several of these.

What is the 12 color theory? ›

Twelve seasons colour analysis comprises four main seasons – Spring, Summer, Autumn and Winter. These are further divided into three sub-seasons each, resulting in twelve colour seasons in total. On the basis of the flow theory, all seasons flow into each other forming a full circle.

What are the 3 basic color theories? ›

However, there are three basic categories of color theory that are logical and useful : The color wheel, color harmony, and the context of how colors are used. Color theories create a logical structure for color.

What is the physics of color? ›

In physics, colour is associated specifically with electromagnetic radiation of a certain range of wavelengths visible to the human eye. Radiation of such wavelengths constitutes that portion of the electromagnetic spectrum known as the visible spectrum—i.e., light.

What is colour correction in physics? ›

Color correction is a process used in stage lighting, photography, television, cinematography, and other disciplines, which uses color gels, or filters, to alter the overall color of the light.

What is one example of colour addition? ›

For example: Red + Blue = Magenta.

What is the color rule of three? ›

The rule of 3 colors is simple: pick one primary color. Then, pick two other complementary colors. See the example below. We picked a main hue (a variation red), and complemented it with two different colors.

Why is it RGB and not Ryb? ›

A student asked, “If the primary colors of the color wheel are Red, Yellow and Blue, why is web color measured in RGB (Red, Green Blue) color?” RGB is what monitors use for colors because monitors give off or “emit” light. The distinction here is that RGB is an additive color palette.

What are the primary colors in physics? ›

In physics, the three primary colors are typically red, green and blue, after the different types of photoreceptor pigments in the cone cells.

How do you mix colors and what is the outcome? ›

Mixing primary colors creates secondary colors

If you combine two primary colors with each other, you get a so-called secondary color. If you mix red and blue, you get violet, yellow and red become orange, blue and yellow become green. If you mix all the primary colors together, you get black.

What colors Cannot be created by mixing? ›

Primary colors - The most basic colors on the color wheel, red, yellow and blue. These colors cannot be made by mixing.

What are the 2 methods of color mixing? ›

There are two main types of color mixing: additive color mixing and subtractive color mixing. Additive color mixing is creating a new color by a process that adds one set of wavelengths to another set of wavelengths. Additive color mixing is what happens when lights of different wavelengths are mixed.

What is the 60 30 10 rule? ›

What is the 60-30-10 Rule? It's a classic decor rule that helps create a color palette for a space. It states that 60% of the room should be a dominant color, 30% should be the secondary color or texture and the last 10% should be an accent.

What is the simplest color scheme? ›

Monochromatic # Monochromatic color schemes are made up of different tones, shades and tints within a specific hue. These are the simplest color schemes to create, as they're all taken from the same hue, making it harder to create a jarring or ugly scheme (though both are still possible).

What are the 4 first colors you can create? ›

In the traditional RYB color wheel, the primary colors are red, yellow and blue. You can create secondary colors—orange, green, and purple—by mixing primary colors.

What are the forbidden colors theory? ›

Red-green and yellow-blue are the so-called "forbidden colors." Composed of pairs of hues whose light frequencies automatically cancel each other out in the human eye, they're supposed to be impossible to see simultaneously. The limitation results from the way we perceive color in the first place.

What are the 4 fundamental colors? ›

The four primary colors in the 4-primary color wheel are blue, yellow, green and red. This differs from the color mixing wheel, which only has three primary colors.

What is it called when you mix white with a color? ›

In color theory, a tint is a mixture of a color with white, which increases lightness, while a shade is a mixture with black, which increases darkness.

What is the paradox of colors? ›

The paradox concerns cases of cerebral achromatopsia, a loss of colour consciousness following cortical injury. Complete cerebral achromatopsics lack any awareness of colour, seeing the world in shades of grey. Bizarrely, however, some such patients show signs of possessing colour constancy.

Is white a color or not? ›

Some consider white to be a color, because white light comprises all hues on the visible light spectrum. And many do consider black to be a color, because you combine other pigments to create it on paper. But in a technical sense, black and white are not colors, they're shades.

What is black color theory? ›

Black # Black is the strongest of the neutral colors. On the positive side, it's commonly associated with power, elegance, and formality. On the negative side, it can be associated with evil, death, and mystery. Black is the traditional color of mourning in many Western countries.

What is the opposite color of pink? ›

The complementary color of pink is directly opposite pink on the color wheel, and in this case, it is green. This is because green is also the complementary color of red, and pink is technically just a lighter shade of red. The complementary green for true pink is very soft, and almost pastel green.

What is the opposite color of red? ›

If you take a look at red on the color wheel, you'll see it is directly across from green. In this article, we are going to look at green as an antonym, or “a word opposite in meaning to another,” of red.

What two colors make red? ›

Know that you cannot make red.

Red is a primary color, so you cannot create it by mixing any other colors. Primary colors are colors that exist on their own and do not contain traces of any other color. Aside from red, the other primary colors are blue and yellow.

What are colors in quantum physics? ›

particle physics

Quarks are said to come in three colours—red, blue, and green. (The opposites of these imaginary colours, minus-red, minus-blue, and minus-green, are ascribed to antiquarks.)

What color has the highest frequency? ›

What colour has the highest frequency?
  • Violet colour light has the highest frequency.
  • The frequency of violet colour light is. 5 × 10 14 Hz .

Is color a spectrum in physics? ›

The visible part of the electromagnetic spectrum is also called a colour spectrum as it consists of seven colours which are arranged from higher energy to lower energy values. Visible colour light is located in the middle of the spectrum. It comprises a very small fraction of the overall electromagnetic spectrum.

What is the color green in physics? ›

green, in physics, light in the wavelength range of 495–570 nanometres, which is in the middle of the visible spectrum. In art, green is a colour on the conventional colour wheel, located between yellow and blue and opposite red, its complement.

What is color by subtraction in physics? ›

Cyan, Magenta and Yellow are the subtractive primary colors. Each one absorbs one of additive primary colors : Cyan absorbs Red, Magenta absorbs Green and Yellow absorbs Blue. Adding two subtractive primary colors filters together will transmit one of the primary additive colors.

How do Colour filters work physics? ›

Colour filters

When white light passes through a coloured filter, all colours are absorbed except for the colour of the filter. For example, an orange filter transmits orange light but absorbs all the other colours.

What is the difference between color addition and subtraction? ›

Additive colors are created by adding colored light to black. On the other hand, subtractive colors are created by completely or partially absorbing (or subtracting) some light wavelengths and reflecting others. Subtractive colors begin as white.

What are the 7 color scheme examples? ›

The seven major color schemes are monochromatic, analogous, complementary, split complementary, triadic, square, and rectangle (or tetradic).

What are the primary and secondary colors in physics? ›

The primary colours are known to be red, blue and green. Then the secondary colour formed by the mixing of red and green is yellow. Yellow is brighter than red and green. The secondary colour formed by the mixing of red and blue is magenta.

How are colors explained in physics? ›

In physics, colour is associated specifically with electromagnetic radiation of a certain range of wavelengths visible to the human eye. Radiation of such wavelengths constitutes that portion of the electromagnetic spectrum known as the visible spectrum—i.e., light.

How does colour work physics? ›

Light is made up of wavelengths of light, and each wavelength is a particular colour. The colour we see is a result of which wavelengths are reflected back to our eyes. The visible spectrum showing the wavelengths of each of the component colours. The spectrum ranges from dark red at 700 nm to violet at 400 nm.

How do you color code physics notes? ›

How to Color Code Your Notes?
  1. Use the Right Tools for Color Coding [highlighters, multi-color pens, colored pencils)
  2. Write First, Color-Code Next!
  3. Stick to a Constant Color Pattern.
  4. Don't Color Code Everything.
  5. Create Your Unique Color Coding Key.
  6. Organize Your Color Coded Notes the Right Way!
Jul 22, 2021

What are color complements in physics? ›

The primary colored circles overlap to produce other colors of light - known as the secondary colors of light: cyan, magenta and yellow. Complementary pairs of light colors are those colors that are exactly opposite each other on the diagram: red and cyan, magenta and green, and blue and yellow.

What are the three colors in physics? ›

In physics, the three primary colors are typically red, green and blue, after the different types of photoreceptor pigments in the cone cells.

What is color in quantum physics? ›

Color is the strong interaction analog to charge in the electromagnetic force. The term "color" was introduced to label a property of the quarks which allowed apparently identical quarks to reside in the same particle, for example, two "up" quarks in the proton.

Is there science behind color theory? ›

Color theory is both the science and art of using color. It explains how humans perceive color; and the visual effects of how colors mix, match or contrast with each other. Color theory also involves the messages colors communicate; and the methods used to replicate color.

Is color theory hard? ›

Color theory can be incredibly complex, however for artists you only need to understand the general fundamentals of color theory. The best way to learn color theory is to purchase a color wheel or better yet, make your own using your own paints.

What is a simple way to explain color theory? ›

Color theory is the collection of rules and guidelines which designers use to communicate with users through appealing color schemes in visual interfaces. To pick the best colors every time, designers use a color wheel and refer to extensive collected knowledge about human optical ability, psychology, culture and more.

How do you do color theory? ›

Color theory also involves a color's darkness or lightness, or color values. You can change a color's hue by adding white for tint, which will give you lighter pastel colors, and black for shade to darken and dull color. When gray is added to a primary, secondary or tertiary color, it creates a tone.

What is color code technique? ›

The 5 Color-Coding Tips You Need To Know
  1. Use Bright Colors. ...
  2. Be Consistent. ...
  3. Only Use Color With The Most Important Information. ...
  4. Distinguish Between Main Ideas And Smaller Details. ...
  5. Avoid Using Too Many Colors.
Aug 9, 2019

How do you find resistance with color coding? ›

Reading and Determining the Resistor Value

Hold the resistor with the gold or silver band to the right and read the color codes from the left to the right. Select the color codes from the bands on the resistor. Read the colors from left to right. The resistance value based on the color code provided is now displayed.

What is triad color scheme? ›

A triad is a color scheme, a special variant of the split-complementary color scheme, with the equal distance between all colors. All three colors are distributed evenly around the color wheel, causing there is no clear dominance of one color.

What are the colors of light in physics? ›

Blue or violet light has the shortest wavelength. White light is a combination of all colors in the color spectrum. It has all the colors of the rainbow. Combining primary colors of light like red, blue, and green creates secondary colors: yellow, cyan, and magenta.


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