Colour harmonies represent a combination or unity of colours that are pleasing to the eye; we use colour harmonies all the time: when we choose an outfit, when we decorate our homes or workplaces, and when we—as designers—want to communicate a meaning or mood.
The Colour Wheel
The colour wheel is the designer’s tool to establish colour relationships, and Johann von Goethe’s mis-named “The Theory of Colours”—there’s no actual theory present—is probably the first text that provided a rational description for the perception of colour arranged as a diametrically opposed wheel. Many have followed on with their own theories and presentations of colour, so we have a couple of centuries or so of established thinking to use as at least a starting point for our work.
Illustrator has twenty-three colour harmonies built in to the Colour Guide Panel, and the Recolour Artwork dialog so in this post we are going to take a look at them, and use it as the basis for further work.
Illustrator’s Colour Wheel is Different
If you’re not already familiar with the RGB and HSB colour models, you may want to check out the Photoshop mini-series “256 Shades of Grey” posts, and if you’re in a hurry, the first two sections of Part Three.
Technically, Illustrator’s colour wheel has more similarity with the LAB wheel but visually, Illustrator’s colour wheel is closer to the RYB model, that has more in common with the traditional artists’ model, with the saturation and brightness elements of the HSB “cylinder” model thrown in but it behaves that way too.
If you know your RGB colour wheel, you’ll know that Red sits at 0º, and Cyan sits diametrically opposed at 180º; here’s what the colour wheel looks like in Illustrator:
You don’t need a diagram to see that opposite red on this wheel is green, and that cyan is a good few degrees around from there; but if you take red and steer it 180º using the sliders in the Recolour Artwork dialog, you end up with cyan!
The reason for this is most probably that unlike Photoshop, which is dealing with luminance values—essentially, working with images made from light—Illustrator is primarily aimed at, er, illustrators (the clue being in the name); illustrators are more concerned with the perceptual values of the end result from the perspective of artists than the production concerns of photographers, and may well have trained in traditional colour theory so the harmonies need to make sense to them.
The Colour Harmonies
In each of the examples below, we will take pure RGB red as a base—or root—colour, and generate a harmony from it. The illustrations show approximately the positions on the colour wheel for each of the colours in the harmony, and underneath the colours generated (white means no colour generated) by the harmony, starting with the original (red) colour; you’ll see that some of the harmonies change the saturation and brightness, as well as the position of the hue.
The Complementary harmony rule generates only one other colour, opposed at 180º.
Illustrator also produces four other variations on the Complementary rule:
In addition to the original colour and the complementary opposite, this rule produces one brightness and one saturation variant on the original colour, with one brightness variation and one hue, saturation and brightness variant on the complement.
Left Complement and Right Complement
These two variations bend the complement clockwise—in the case of the left—and counter-clockwise for the right, with hue, saturation and brightness shifts.
The Analogous harmony generates four additional colours, with hue values spaced 15º and 30º clockwise and counter-clockwise from the original colour, with saturation and brightness variations.
The Analogous 2 variant produces five additional colours, with less hue variation and deeper saturation and brightness modulations.
Monochromatic, Monochromatic 2 and Shades
As you’d probably expect, these rules fix the hue, and instead generate variations in saturation and brightness. Monochromatic produces three additional variants with decreased variations in saturation of 75%, 50% and 25%.
Monochromatic 2 yields four saturation and brightness variations.
Shades generates three additional brightness-varied colours.
Illustrator has a trio of triadic harmonies, which all split from the original colour by 120º. The first of these—Triad—produces two additional hue shifts with some saturation variation.
This harmony rule creates the two additional hue-rotated swatches as in the original Triad harmony, but with an additional modulations of brightness/saturation for the original colour and the rightmost complement.
The tetrads are roughly-speaking square—or perhaps diamond—variations. The original Tetrad generates three additional colours hue-rotated by 90º and with a 5% decrease in saturation. Tetrads usually consist of two pairs of complimentary colours.
This rule gives us a total of five colours, with a variation on the root colour, along with three other saturation and brightness varied colours, with the colours to the left and right of the root additionally being skewed a bit further in hue. This is most like a fusion of the direct complement, with a left and right complement combination.
The Tetrad 3 harmony again gives us a five colour rule, with a darker variation of the base colour, a less saturated version of the complement and then a rotation of the second complementary pair by an additional 15º, with modulation of the brightness/saturation.
The compounds—1 and 2—are again clockwise and counter-clockwise variations of each other. These rules are compounded analogous and complementaries. In Compound 1 you can see analogous colours to the red and then analogous colours from the green complement. Compound 2 moves the complement in the opposite direction.
There are four high-contrast harmonies, all of which are fundamentally triads—certainly in terms of hue—but also compounds of other harmonies.
High Contrast 1
This rule consists of five colours; it has a monochromatic variation an left-analogous variation of the base colour, with a left complement with a saturation/brightness variant of that.
High Contrast 2
The only rule of this group to generate six colours, High Contrast 2 is an equally distributed Triad of 120º, with saturation and brightness modulations of each hue.
High Contrast 3
This harmony creates an analogous variant, along with a brightness-modulated variant of the analogy, with a 90º counter-clockwise hue variation that have saturation/brightness modulations.
High Contrast 4
High Contrast 4 is almost identical to High Contrast 1, but here the analogous colour to the root colour is from the right, and two variants are produced from it, rather than the base as in High Contrast 1.
The final rule in the Illustrator harmonies is the Pentagram, yielding a total of five components (as you’d likely expect) separated by 72º in hue, with various modulations of saturation and brightness.
The important thing to remember here is that these variations are often just a starting point. Rules are there to be broken, and it is one of the tools we want to make a statement, or otherwise create a purposeful imbalance to arouse curiosity or invoke emotional responses.
The Colour App and Service
We are surrounded by some great colour combinations, and the Colour CC app for iPhone is a great way to capture and model your own colour harmonies that then become immediately available in all of your CC applications. They can also be shared with your colleagues using CC Libraries, or with The World via the Colour web service at colour.adobe.com—it’s a great way to have fun with experimenting in colour combinations, and putting them to use straight away.