Before you begin

An interactive course in color perception.

It frustrates me to no end that all courses on color theory are static. I can read books, I can listen to videos, but when I want to test my hand at using a concept I’m left without feedback. As someone who hasn’t, doesn’t, and won’t attend art school, it seems that there are no materials geared towards my learning.

In response to my frustration I made all the widgets in this book. I use them as a way to pick colors for side projects. These widgets are useful to me, but until recently, they weren’t published anywhere for others to use also; I hope this book changes that. Yes, most of the text was written by Claude, I’ve read some of it, I’ve rewritten some of it, and I’m working through the remaining bits. I hope the book is informational, and if nothing else, fun to interact with.

How to read this book

Albers wrote his exercises for paper. You are reading them on a screen, and a screen does not behave like paper. Paper reflects light; it shows you a color by absorbing the rest of the spectrum. A screen emits light, mixed from three subpixels at intensities chosen by your operating system. The same RGB value in this stylesheet becomes a slightly different color on every device that renders it, and on every device the rendering shifts again with your settings and the room you are sitting in.

The exercises depend on small differences — a grey that looks warm beside one blue and cool beside another, two patches that appear identical until you separate them. If your display is fighting you, the lesson never lands.

What your screen is doing

If you are on a Mac, True Tone is probably on. It samples ambient light and warms or cools the display’s white point to “match” the room. The result is a display whose color shifts continuously as the light around you changes — helpful for reading email, ruinous for an exercise about whether two patches look the same.

Night Shift on macOS, Night Light on Windows, and f.lux all do something coarser: after a chosen hour they pull the entire display toward orange, on the theory that blue light disturbs sleep. They distort every hue relationship the exercises ask you to see.

Beyond those: every panel has its own factory calibration, color gamut, and gamma curve. An OLED phone, an LCD laptop, and an external monitor will render the same swatch as three perceptibly different colors. There is no neutral display.

The room is part of the display

Your eye does not see a screen in isolation. It sees the screen against everything else in your visual field — the wall behind it, the lamp beside you, daylight from a window. In a dark room, the screen appears to have more contrast than it really has; in a bright room, less. The Bartleson–Breneman effect is the technical name for this; you can verify it now by dimming the lights.

Strong directional light — a window across from you, a lamp behind the screen — adds glare and washes the image. A reflection on the glass adds a color you did not ask for.

What to do

For the duration of these exercises:

• Turn off True Tone, Night Shift, Night Light, f.lux, and any “adaptive” display setting.

• Set brightness somewhere in the middle and leave it alone. Auto-brightness should be off.

• Sit in moderate, indirect ambient light. Not a dark room, not direct sun.

• Use the same device, in the same place, for any single exercise.

None of this gives you a calibrated display. It gives you a consistent one — consistent enough that when the book says “look at these two greys,” the two greys you see are the two greys the book meant to show you.