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Two [complementary] colors make a strange pair. They are opposite, they require each other. They incite each other to maximum vividness when adjacent; and they annihilate each other, to gray-black, when mixed—like fire and water.
Johannes Itten, The Art of Color

Complementary Colors: SCIENCE!

Explaining complementary colors is my favorite part of teaching color theory, because their effect on the eye is objective. How complementary colors work isn’t a matter of taste or feeling. It’s science. And if you know me, you know I am a big fan of science.

Complementary colors are colors that are directly across from each other on the color wheel. They can be described as the opposite of each other because, when mixed in correct proportion (for example, in paint or in dyes for yarn or fabric), they create a neutral gray. When used together, complementary colors create a strong, bold effect, which is why they are ubiquitous in athletic uniforms, graffiti, and murals like this one around the corner from my house.


Here’s the science behind this in a nutshell: When you look at a color—for example, red—and then look at a white surface, an afterimage of the complementary color (in this case, green) will appear. The eye wants to see the color’s complement, so pairing complementary colors is visually satisfying. I’ll take this opportunity to recommend the Stuff You Should Know podcast “How Color Works.”

In the MDK Shop
The mother of all gradient hand-dyed yarns in dazzling slow motion.
By Freia Fine Handpaints

From Science to Art and Design

The strongest pairs of complementary colors use the three primary colors: red, blue, and yellow. The complementary color pairs are therefore red and green, blue and orange, and yellow and purple.

I designed the Complementary Cowl to demonstrate these pairs. The vertical stripe of colors was inspired by color studies that students in Johannes Itten’s class at the Bauhaus school painted. In these exercises, students mixed colors to move across the color wheel from one complementary color to the other.

Using the box of St-Denis Boreale that Interweave sent me, I did my best to recreate these studies for the three primary colors and their complements. Each end of each swatch is a hue (well, the orange isn’t a hue because Boreale does not include an orange hue, which is not unusual for yarn lines), and the two colors between the hues are tints, tones, or shades of the hues. (For a detailed discussion of tints, tones, and shades, read Part II of this series.) The farther one gets from the true hues of a color (at the outermost edge of the color wheel), the less contrast exists between that color and any other color. These swatch color studies take two high-contrast colors—as close to the true hues as a yarn palette permits—and bridge the gap between them with lower-contrast versions of the same hues.

Complementary colors are one of my go-to design techniques. I’ve used them in my swatch for the Linear Systems hat, the final version of which was knit in an excellent light-dark contrast rather than complementary colors, and the Annular Mitts.

Most recently, I built the color scheme of my Braid-o-Rama cowl around blue-orange and purple-yellow contrast, using hues, tones, and shades of these colors. Like Itten notes, these colors might seem like strange pairs until they’re knit up, at which point they’re vivid and eye-catching.

For examples of complementary colors in fine art, consider Van Gogh’s paintings. The Starry Night: purple and yellow and blue and orange. The Night Café: red and green. Café Terrace at Night: all the complementary colors. The emotions these paintings evoke comes as much from their color combinations as their subject matter.

The Red-Green Complement: It’s Not Great.

Purple and yellow and blue and orange are easy complements to use; red and green are more challenging for two reasons.

First, this.

Red and green don’t have an immediate Christmas connotation in all cultures, but there’s no escaping this association in the United States and much of Europe.

Second, this.

The bottom image is red and green hues in grayscale: nearly identical. Purple and yellow and blue and orange hues have inherent light-dark contrast; red and green do not. As a result, by pairing blue and orange and purple and yellow as I have in Braid-o-Rama and the Linear Systems swatch, you have two types of contrast: complementary and light-dark. If you’re working with tints, tones, or shades of purple, yellow, blue, and orange, this won’t necessarily be the case (consider the blue and orange Annular Mitts, in which the orange is slightly darker than the blue).

You Don’t Have to Go Crazy

As I discussed in Part II, each color encompasses all the tints, tones, and shades, so complementary colors can be deep, rusty orange and pale gray-blue. They can be tertiary colors, such as red-violet and yellow-green. If you’re looking for a color to pair with turquoise, I recommend gathering all the orange, red-orange, and yellow-orange yarns from your stash or in the shop, from the lightest to the darkest—and considering them one at a time. I think you’ll find a combination you like. Thank you, science!

About The Author

Ann Weaver lives in Baltimore, where she works as a freelance editor and writer and spends her free time volunteering and working to bring change to her community. You can follow Ann on Instagram and find her designs on Ravelry, where her username is weaverknits.


  • Purple and yellow always makes me happy.

  • Interesting. The mitts are pretty.

  • Okay, now I want to know why yarn lines commonly skip orange. Is it just unpopular, or is it Science?

    Personally I find “pure” orange unpleasant unless it is either paired with black or sandwiched between its red-and-yellow primaries. The hues can be lovely though.

    • A lot of people find pure orange unpleasant–it’s a slow seller, which is why many yarn lines don’t have a true orange. If people buy orange, they tend to buy only one skein rather than a sweater’s worth (even I have only two sweaters in which pure orange is the main color, and I’m an advocate for orange)!

      • I knit myself a sweater in a saturated orange shade last year (Spud and Chloe Sweater ‘Firecracker’), and I get all kinds of comments on the colour when I’m out and about. Seems like it’s a colour that really polarises people.

    • I agree – I often want to use a tint or shade based on a pretty straightforward orange hue for colorwork but it’s frustrating to find it in the weight and fiber I’m looking for. I guess whoever makes these choices at the yarn companies must have in mind whether customers would want to make a whole sweater or shawl out of their colors and wouldn’t want plain old orange (or yellow, which I’ve also had trouble finding in a straightforward hue).

    • Such a good question—I love orange hues, too. We have a pumpkin color yarn coming in soon that really is delicious.

  • My favorite colors are in the red to red-orange range: pinks and corals. It wasn’t until I really looked into color theory that I realized why I like aqua and turquoise so much – they’re complements of red to red-orange. And then I also understood why I like turquoise and brown together- brown is in the red-orange range.

    • Hey, me too. Thanks!

  • I love this series by Ann. Science is so fascinating when applied to (my) life. And also when it’s not. 😉

  • Fascinating. I always say, “I love red and green together, and not just at Christmas!” I’m odd, so I wonder if it pleases me because of the “scientific” lack of true contrast. I also love most colors, and complementary color combinations in general, so the “picking out colors” portion of a knitting product is something that I greatly enjoy.

    • It cheers me to hear that knitters appreciate red and green together. Although red and green do not have the light/dark contrast that purple and yellow and blue and orange have, their complimentary contrast still draws the eye. And I think a lot of people LIKE red and green together but just can’t get past the Christmas association!

  • Please re-subscribe me to daily briefings. My finger twitched, and that quickly, I became unsubscribed. Sad face.

  • I love complementary colors. Ann Weaver’s guides always leave me wanting to play with combinations. Just realized I am sitting on my back porch with 3 red vintage leather chairs and lots of red accessories. On three sides I m surrounded by windows with green grass, wild currant bushes, pines, spruce, and maples. It will not feel like Christmas til winter when snow comes.

  • I REALLY want to know something about that mural!

    • I saw the artists creating the mural, but instead of stopping and asking them about it, I just yelled out, “Awesome work!” and kept walking. I am an idiot.

  • Nice explanation!

  • Now I’m thinking maybe this partially explains the popularity of Christmas. Red and green just feel good. (At least to me!)

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