HSB color model : a visual guide for adjusting colors

HSB (HSV) makes color adjustment easy. You can use HSB color model in most graphic design software.

HSB components are hue (H), saturation (S) and brightness (B). When you understand what they do, you get fast and effective at tuning colors.

Hue

Hue is the “essence” of most color. It is expressed as degrees from 0° to 360°. Thus it is often visualized as a color circle.

HSB colors are 0° red, 30° orange, 60° yellow, 90° yellowish green, 120° green, 150° mint or sea foam, 180° cyan, 210° light blue, 240° blue, 270° purple, 300° magenta or pink, and 330° crimson red.

Saturation

A saturation value expresses how much white (or gray) a color has. 100% means full color, 0% white (or gray).

HSB color wheel with 100% saturation and 99% brightnessHSB color wheel with 66% saturation and 100% brightnessHSB color wheel with 33% saturation and 100% brightnessHSB color wheel with 0% saturation and 100% brightness
Color circles above have same brightness of 99%. Their saturations are 100%, 66%, 33% and 0%.

Brightness

A brightness value expresses how much black a color has. 100% means full color and 0% pure black.

HSB color wheel with 100% saturation and 100% brightnessHSB color wheel with 100% saturation and 66% brightnessHSB color wheel with 100% saturation and 33% brightnessHSB color wheel with 100% saturation and 0% brightness
Color circles above have brightnesses 100%, 66%, 33% and 0%. All have 100% saturation.

Hue as a box of gradients

In its color pickers, Sketch app has a gradient box for adjusting saturation and brightness of a hue. Horizontal axis shows saturation, and vertical axis brightness of a color.

White and black are not opposites of each other in HSB color model. White is a corner, but black an edge of the box.
Sketch color picker gradient box for a 90° yellowish green. It shows all color variations for this hue.
White and black are not opposites of each other in HSB color model. White is a corner, but black an edge of the box.

Luminosity

Some hues are luminous and others more dark. Luminosity differences become evident, when you make a color circle grayscale (image below).

HSB color circle with hues in grayscale. It shows that hues have different luminosities.

Pure red (0°), green (120°) and blue (240°) hues are dark by nature. On the other hand, yellow (60°), cyan (180°) and magenta (300°) have high luminosities. Below diagram visualizes luminosities on vertical axis.

 

This bar style diagram visualizes that HSB color model hues have different luminosities each. This is a mobile version of the image.

This bar style diagram visualizes that HSB color model hues have different luminosities each. This is a desktop version of the image.

 

Few hues, many values

Visual identities often have a main hue. Even a single hue gives diverse options, when you vary brightness and saturation.

A screenshot of a single hue layout : Dropbox mobile app

Dropbox Android app has a single hue visual style. The hue of its blue is ~210°.

Status bar and toolbar have saturations close to 100%. Yet floating action button fill has only ~50% saturation, and folder icon just 4% saturation. Thus the latter two fill colors look like they contain some white.

I found the single hue idea first in Jennifer Tidwell’s book Designing Interfaces (O’Reilly 2006). Her design pattern Few hues, many values elaborates this idea (p. 294-296).

Darkening by hue shift

In a current project, I designed a facet modal. Visual identity was single hue. Its only brand color was ~180° cyan, which is a high luminosity hue.

I wanted to tell that “you come to a different place”, when you open the facet modal. Thus I wanted the modal to have a dark background.
A screenshot from a single hue layout with cyan accent color
I wanted to tell that “you come to a different place”, when you open the facet modal. Thus I wanted the modal to have a dark background.

50% and 10% saturated, dark cyans look unpolished as background colors of this facet. See images below.

Dark cyan as facet background color : 50% and 10% saturated variations

50% saturated version (left column) reminds me of early 1900’s art nouveau. That is too far from the Apple iOS like original style. In a way I like this one, though.

A 10% saturated background looks mostly gray. That is not horrible either. Yet I wanted a more branded style here.

I then shifted the original, cyan accent color towards blue by 15—20°. A slightly purer blue (~200°) maintains the feel of the brand color. Yet its dark variants look quite neutral. See image below.

A layout where cyan accent color has been modified to dark UI background color by a 15 degrees hue shift

The new dark UI has same accent color as the original layout. Its toggle buttons and arrowheads have the cyan hue. Same accent color integrates the dark and light parts to one UI.

In the beginning, I had only a vibrant accent color. Then understanding HSB color model helped me to create a discreet and coherent dark background color out of it.

A learning game for HSB color model

You get effective at adjusting colors, when you remember by heart, what hue values colors have. A sense of hue luminosities makes selecting colors even easier. Erik D. Kennedy’s Color guessing game for HSB color model lets you train these and more color skills.

A screenshot from Erik D. Kennedy’s Color guessing game for HSB color model. It shows how reds can look somewhat saturated and dark also, when saturation is low and brightness high.

Following points help you to learn HSB color model faster, and score better in the color game.

  1. If a color looks like it has some white (“tinted”), it might have low to mid range saturation (0% to 75% S).
  2. If a color looks partly black (“shaded”), its saturation might be low (0% to 33% B).

Similar looking colors can have very different saturation and brightness values. For example, reds can look somewhat saturated and dark also, when saturation is low and brightness high (image above). Thus it is useful to have a sense, how saturation and brightness affect distinct hues.

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