Notes on Colour and Contrast

Colour choices are usually argued about in terms of taste, which is why the arguments do not resolve. Contrast is not a matter of taste. It is measurable, and it decides whether the text can be read at all.

A palette can be entirely to one person's taste and still fail in ordinary conditions: a phone screen outdoors, an older monitor, a room with the blinds open. The colours have not changed — the difference between them has stopped being large enough.

Pick the two colours that have to work hardest — body text and its background — and settle those first. Everything else in the palette is decoration and can be adjusted around them.

The practical test is unglamorous: view the page at arm's length, then in daylight, then at half brightness. Anything that disappears in one of those three was never really legible; it was legible under ideal conditions, which is a different thing.