You need 4 colors

Original Article ↗ Hacker News Discussion ↗

Visual quality & usability of the demo

  • Many describe the provided palettes as ugly, garish, or physically straining to look at, especially in light mode.
  • Some find a few specific hues acceptable, but “not the worst” is often the faint praise.
  • Common complaints: background too saturated, overall page feels “foggy,” poor hierarchy, and low contrast.
  • A few commenters do like certain ranges (e.g., around specific hue values) or the general idea of a 1‑D slider-driven palette.

“Four colors” as a design principle

  • Several argue that “you need 4 colors” is a misleading oversimplification.
  • Real interfaces need more colors/roles for errors, warnings, destructive actions, hover/focus/disabled states, borders, etc.
  • Others say you can make good UIs with fewer colors (even monochrome), citing early Mac interfaces.
  • The text itself is called self‑contradictory: it says you “need 4” but describes one as “optional.”

Accessibility and contrast

  • Multiple people note that many combinations fail standard contrast checks; some button text becomes nearly invisible.
  • There is consensus that color alone should not convey mission‑critical information; shape, position, and other cues are needed.
  • Debate appears on color‑blind operators: some argue systems must accommodate them; one voice suggests excluding them in certain safety‑critical roles.

Color tools, algorithms, and color spaces

  • Alternatives like uiColors, Huemint, and Material You / Android color utilities are cited as more practical or better‑looking.
  • Commenters note that simply rotating HSL hue is crude; perceptual spaces like OKLCH or HCT (CAM16‑based) behave better and can embed contrast guarantees.
  • There’s skepticism that any simple formula can always generate pleasing palettes given human and cultural variation.

Color systems, roles, and design tokens

  • One detailed thread distinguishes “brand” palettes (primary, secondary, accent, neutral) from “role” tokens (copy text, background, button states, etc.).
  • Claim: compressing everything into 3–4 “colors” for text/bg/button quickly breaks down; a proper system has more swatches plus mapping between layers.

Language/grammar digression

  • The site’s “How it works?” label triggers a long side discussion on English question formation.
  • Views range from strict prescriptivism (“wrong, distracting”) to tolerance (“language evolves,” “non‑native speakers”).
  • Some emphasize that even small grammatical slips can increase cognitive load, especially on UI copy.

Historical and meta observations

  • References to Amiga, CGA, four‑color theorem, and monochrome systems show that hard limits on colors are not new.
  • Some suspect the page partly exists to provoke opinionated debate.
  • A few users share personal color‑scheme generators (e.g., driven by current temperature or date).