The year was 1928 when artist Robert Dorr discovered that all colors - red, yellow, blue, black, white - and all the thousands of shades of these colors - contained undertones, no matter how subtle, of either blue or yellow.
He found that all colors with blue pigmentation worked together in harmony, and all colors with yellow pigmentation worked together in harmony. Only when blue-pigmented colors were mixed with yellow-pigmented colors was there discord.
Why It Matters
This concept was revolutionary for fashion, interior decorating, marketing, and much more. You are either blue or yellow based, and therefore look better in colors of your undertone.
Rooms that utilize colors from one undertone feel better and more harmonious than if there is a mixture of blue and yellow based colors.
This plays a part in designing clothing fabrics as well, and most sales racks are full of mixed key clothing. We naturally become repelled when we see mixed spectrum palettes. In fact, clowns mix color spectrums on purpose to create a jarring effect!
Having this knowledge is a game changer for looking your best and designing at a top notch level.
Training Your Eye
Some colors are obviously blue or yellow based, while others are hard to differentiate. I was raised with knowledge of the blue base yellow base color system, so I have an easier time knowing undertone, but sometimes I still have a hard time when colors are on the cusp. A color is on the cusp if they are only slightly more blue pigmented or slightly more yellow pigmented.
Here is a breakdown of blue versus yellow based undertones, so you can start to train your eye to the two color wheels.
Please note: The only two colors of the rainbow that cannot be the other spectrum are true orange and true burgundy. True orange will always be yellow based, and burgundy will always be blue based.
Also note: There is no such thing as a neutral color. Black is not just black, and white is not just white. There is no such thing as a "universal color", or a shirt that can "go with everything", because everything we see with our naked eye is either blue or yellow based!
Since color names can look different to you than me, I have added pictures so you can see the colors I am referring to.
These colors are pulled from Renae Knapp and Dee Dorr's book, Beyond The Color Explosion: The Color Key Program.
Blue Based: ruby, maroon, burgundy
Yellow Based: fire-engine red, warm red, watermelon
Blue Based: daffodil, lemon, icy yellow
Yellow Based: mustard, butterscotch
Blue Based: royal blue, turquoise, purple-navy, robin's egg blue
Yellow Based: greyed/ muted navy, black navy, baby-blue, sky-blue
Blue Based: blue-green, forest-green, seafoam
Yellow Based: olive, moss, yellow-green, (fern, yellow khaki)
Blue Based: coffee, mahogany, deep reddish brown, (pink brown, chocolate)
Yellow Based: bronze, camel, bamboo, (suntan)
Blue Based: cinnamon, ranch-house rust
Yellow Based: orange-rust
Blue Based: pink or rosy beige
Yellow Based: buff or yellow-beige
Blue Based: hot pink, fuchsia, rose, mocha
Yellow Based: coral, salmon, shrimp, tangerine
Blue Based: blue-black, jet, raven
Yellow Based: umber-black, charcoal, golden black, ash
Blue Based: blue-greys
Yellow Based: yellow-grey, brown-grey
Blue Based: snow, blue-white, white-white
Yellow Based: cream, bone white, winter-wool white
When you combine colors from one base only, it is impossible to make a mistake. This eliminates all trial-and-error, all guesswork, and gives you a foolproof formula for success in working with color in all areas of your life.
This scientifically proven system is not a fad or a gimmick, it does not change with the fashion trends, but is as basic, unchanging, and natural as you are.
You probably noticed that you liked blue based or yellow based colors over the others. This is because nine times out of ten you will be drawn to colors in your spectrum. You are born into a color group, and love the color of you.