HueComb

Dark Knight

#151931

A blue that is nearly neutral — the hue shows only against a true grey. It is dark — it carries white text and needs care with black.

Hex

#151931

RGB

21, 25, 49

OKLCh

22.3% 0.047 274.8°

CIELAB (D50)

9.4, 4.4, -16.8

What is true of this colour, and of no other

  • No other named colour in the set is within ΔE00 2 of it — it stands alone.
  • It uses only 33% 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 104.1; on black, Lc 0.0. 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.
  • All three dichromacies see it as very nearly the same colour you do: its hue is not the part carrying its identity.

Text on this colour

White text

17.28:1 — passes AA

Black text

1.22:1 — fails AA

White text is the better of the two at17.28:1. That is enough for body text.

The same colour, with one cone missing

As you see it

#151931

protanopia

#191931 · ΔE00 1.9

deuteranopia

#181831 · ΔE00 2.0

tritanopia

#171736 · ΔE00 3.4

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isLiberty Blue at ΔE00 2.192: between 2 and 5 — clearly two colours when compared, easily mistaken from memory. What the numbers mean.

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