Optical Color Mixing

There are two ways color is mixed to make new colors. One is commonly known as admixing. The other is optical mixing, also known as optical fusion or perceptual mixing.

What is admixing?

Admixing is the process of blending pigmented color together to form a new color. So we take red and yellow paid and depending upon the proportions that we use we can get a red orange and orange or yellow orange. Or, we take blue and orange and blend them to create browns and gray.

Through admixing we create a color and then apply it to the surface. We can see what the color will be before we apply it. In optical fusion, 2 or more colors placed near each other create the illusion of new colors.

Admixing is used for pigment colors, including all sorts of paints and dry media, dyes, inks, crayons, food coloring, and other colorants. (Anything that has color contains pigment). When you are using devices or viewing computer or television screens, color is not admixed, but optically mixed.

What is optical color mixing?

Optical mixing, also known as partitive color, is the perception of color resulting from the combination of adjacent colors. In other words,  when color is mixed optically, the blending occurs perceptually, and takes place between our eyes and our brain. The perceived blending of color increases with distance. When you look closely at a television screen or computer display you will see the screen is divided into a grid or network of pixels. Each pixel is capable of displaying different colors depending on the electronic information it is receiving. So a group of red pixels intermingled with a group of yellow pixels will not actually blend into orange, but will be perceived as orange (a mixture of red and yellow). What specific orange we see depends upon the ratio of red to yellow pixels involved.

This is all a very simple way of explaining the difference between optical color mixing and traditional admixing of pigments.

 

optical color mixing

 

Optical fusion is accomplished with pigments as well as light. In 4-color process printing, four different ink colors — cyan, magenta, yellow and black — are laid down in various proportions and densities to create a full-color continuous tone image. Getting up close to a printed image reveals that the image is made of individual dots of color. The more dots and the smaller they are, the more refined an image appears.

Optical fusion also occurs in other media such as woven fabrics and mosaics.

 

Optical fusion is not a result of digital media.

About the time that photography started developing (pun intended) in the 1800s, Artist began experimenting with optical mixtures and light impression. The Impressionists, especially the Pointillists, laid down small areas of color and allowed them to fuse visually to create images. French artist Georges Seurat is known for his wall-sized paintings composed of colored dots.

Let’s take a look a work by Hippolyte Petitjean, a lesser known neoimpressionist painter. In the larger image, the individual colors are clearly seen. The artist used the proximity, size and frequency of the colored brushstrokes and the surface of the paper itself to create the impression of other colors that don’t exist in the painting but are perceived.

 

Since optical fusion requires small areas of color or distance, either by the actual size of the colored shapes or by increasing the viewing distance, we can reduce the size of the image, making the colors fuse optically into a continuous tone impression so the the image becomes more solidified.

Contemporary painters and illustrators who make use of optical fusion include Thomas Blackshear, Mark English, Chuck Close, among many others.

 

Why is optical fusion important to understand?

There are a number of reasons:

Optical mixing helps us understand that color is perception. Our perception of color changes based on the quality of light, what colors are present in our visual field, and how colors interact with themselves and our visual mechanisms.

The colors you see on your device or computer display as you’re reading this article are constructed of tiny units —  pixels — each with its own color assignment. The pixels fuse optically to create the colors you see.

When you admix colors, more often than not the resulting color will appear duller than the colors you began with. This is because any time non-spectral colors (hues) are blended, they lose saturation. Remember, you can mix pigment primaries — red, yellow and blue or magenta, yellow and cyan — to make an almost-black gray. Gray has no saturation. It’s truly neutral. With optical mixing, colors retain their saturation and can retain their brilliance. There is some “additive” dulling, but not to the extent of what happens when pigment colors are blended.

Whenever you print a digital image, the print, which is made of pigment colors, appears differently than what you see on screen.

We perceive and experience color in a variety of ways. Designers and artists need to build their perceptual skills and sensitivity to color nuances. Since we work in color, we need to understand how it works in order to make appropriate color decisions. While color tends to shift and change, it’s still a fact-based, scientific and objective design element.

Alvalyn Lundgren

Alvalyn Lundgren is the founder and design director at Alvalyn Creative, an independent practice near Thousand Oaks, California. She creates visual branding, publications and books for business, entrepreneurs and authors. She is the creator of Freelance Road Trip — a business roadmap program for creative freelancers. Contact her for your visual branding, graphic and digital design needs. Join her on Twitter, Facebook, Instagram, and subscribe to her free monthly newsletter.

This Post Has 9 Comments

  1. Rabecca

    The question I had was how to mix colors with your eyes. This is kind of helpful. Hopefully next time you can answer my question. Thanks anyway:)

    1. Alvalyn Lundgren

      Hey, Rabecca: There’s only one way to mix colors “with your eyes” and that’s optical color mixing. Are you asking because you’re working on a school assignment?

  2. ARante

    Can I asked Mixing of pigments dyes in textile,can we could consider,volume of water?weight of fabric? vs weight of pigment dyes?
    why during pigment process the effect of dye become lighter and less saturated?
    during mixing can we add water or just a combination of pigment only?

    1. Alvalyn Lundgren

      Thanks for your questions.

      The proportion of pigment to water affects the saturation of the color, just like with watercolor and gouache. The more you dilute the pigment, the less saturated it becomes. This is true with any wet media. It’s a matter of proportion.

      I don’t work with dyes or textiles, so I can’t answer your question about volume of water and weight of fabric.

      If you want to know about dyeing textiles I recommend “Googling” on that topic, specifically. There’s a wealth of information out there.

  3. Karen Foss

    Thank you for a clear and excellent explanation.

  4. Adna

    hello!
    I am young artist and i need your help.
    I see that you are good artist so could you make more things like these.
    My question is how do we use colors on this type of art.
    Do we use primary colors or we can use all shades that are possible?
    Can we put colors on random places (on each other) or we have to do it so carefully to between two dots we can see a bit of white?
    Do we use acrylics and if we,then which type of?
    Thanks you if you answer my question

    1. Alvalyn Lundgren

      You can use any colors. It’s the size and proximity that make the optical fusion work. If you’re working on a white surface, you can simply not place any color in the areas where you want white. Optical fusion works no matter what medium you work in. It will work with colored pencils, oil paints, and printers inks as in four color process printing. Optical fusion is also at work on your phone, laptop, desktop, and television screen.

  5. nancy ori

    This is all very interesting until you got to the part about yellow on the computer screen. I hope you know that there are no yellow dots. There are only red, green and blue dots of phosphorus light being emitted. There is no yellow. The yellow is the whole point of you discussing optical mixing. Yellow is created in our brain, which also has only red, green and blue rod and cone receptors of light. Overlapping the discussion of how we see color on our devices with how artists mix paint is a slippery slope. You are confusing any beginner reading this article. You are talking about two entirely different color wheels….one dealing with colored light and one dealing with colored pigments. There is also a third color wheel for those of use who print our photographs. If you want to discuss this or have comments, please feel free to contact me.

    1. Alvalyn Lundgren

      Hi, Nancy:

      Did I actually state that yellow “dots” are present on digital screens? No. I didn’t state that there are “yellow dots” on displays.

      Each pixel in a display fires red, green, or blue, or various combinations of R, G, and B, altogether (resulting in white) or not at all (resulting in black). We’ll see a pixel as yellow if red and green phosphors are firing together.

      Yellow is a secondary hue in the additive color system, and is created by mixing red and green light. Yellow, an additive secondary hue, is the complement of blue, an additive primary.

      https://youtu.be/GcOmikDK5Uw

      Yellow is a subtractive system primary (its complement is violet — the blend of the other two subtractive primaries), and is the result of the reflection of red and green light from pigment (colorant).
      There are two top-level color systems: additive and subtractive. Additive deals with direct light, and the primary hues are red, green and blue. The subtractive is the traditional RYB, and the technical or “process” color wheel using CMY. Also note that cyan is a blue, and magenta is a red.

      I don’t agree with you that I’m confusing people. I’ve taught color theory in design programs to designers, artists, and photographers since the early 90s. I teach color theory in both traditional and digital media, and I work professionally in both media. My curriculum is sound, and knowledge is true.

      I think we actually agree in theory how yellow, magenta, and cyan are generated in light from the additive primaries, and that optical fusion is present in digital work and color printing.

      Your black and white portraiture is lovely, by the way.

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