Acoustic Brown

#766b69

A neutral that has no useful hue — it reads as a grey. It is mid — the hardest range to put text on, either colour struggles.

Hex

#766b69

RGB

118, 107, 105

OKLCh

53.7% 0.014 29.9°

CIELAB (D50)

46.2, 4.2, 2.8

What is true of this colour, and of no other

  • 2 other named colours sit within ΔE00 2 of it.
  • It uses only 7% of the chroma available at this lightness and hue — there is a far more vivid version of this colour inside sRGB.
  • As text on white it measures APCA Lc 75.5; on black, Lc -26.2. The sign is the polarity, which the WCAG ratio discards.
  • Built into an eleven-step scale, 10 of the 10 adjacent pairs stay ΔE00 2 apart — see the ramp.
  • protanopia and deuteranopia and tritanopia shift it by ΔE00 6.4 and 7.0 and 20.9 — no red cone.

Text on this colour

White text

5.15:1 — passes AA

Black text

4.08:1 — large text only

White text is the better of the two at5.15:1. That is enough for body text.

The same colour, with one cone missing

As you see it

#766b69

protanopia

#6c6c69 · ΔE00 6.4

deuteranopia

#6e6e69 · ΔE00 7.0

tritanopia

#717137 · ΔE00 20.9

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isWarm Haze at ΔE00 0.99: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.

  • Warm HazeΔE00 0.99 · #736967
  • Night SkyscraperΔE00 1.023 · #756968
  • Eagle EyeΔE00 2.09 · #736665
  • Hickory CliffΔE00 2.147 · #7c6e6d
  • EmuΔE00 2.207 · #756e6d
  • Sultry SpellΔE00 2.273 · #716563
  • Chocolate PuddingΔE00 2.325 · #6f6665
  • GrapyΔE00 2.467 · #786e70
  • Simple SilhouetteΔE00 2.487 · #7a716e
  • Mauve MoleΔE00 2.512 · #7d716e
  • SophomoreΔE00 2.586 · #7d7170
  • ImageryΔE00 2.609 · #7a6e70

12 of these have no page of their own: pages exist for the 4,961 colours the dataset marks as good names.