Never pure black

How to apply it

1. 1

   Replace every #000000 text and background value with the palette near-black, #0f172a.

2. 2

   Pair it with an off-white ground rather than pure #ffffff, so neither end of the range sits at the extreme.

3. 3

   Grep for #000, #000000, and rgb(0 0 0) literals before shipping, dark-mode surfaces included.

4. 4

   Treat dark mode separately: a pure-black surface makes white text bloom the same way, so raise it off zero too.

Why it works

#000000 on #ffffff is the largest luminance step a screen can produce, about 21:1, and at that extreme the white ground appears to encroach on the thin parts of every stroke, so edges look over-sharp and long reads get tiring. A near-black blue-grey such as #0f172a still measures 17.9:1, far above the 4.5:1 AA floor, while pulling the step back from the maximum. The slight blue cast also matches the cool white most displays emit, so the text reads as ink instead of a hole punched through the screen.

What breaks

A long article set in #000000 on #ffffff has stroke edges that appear to shimmer as the eye moves, and readers describe the page as harsh or fatiguing after a few paragraphs without being able to point at what is wrong.

Review questions

1. 1

   Is any text or background using literal #000000?

2. 2

   Do stroke edges look settled rather than shimmering against the background?

3. 3

   Are the darkest tokens a near-black with a slight hue rather than true black?