HueComb

Rare Red

#dd1133

A red that is about as vivid as sRGB can show at this lightness. It is mid — the hardest range to put text on, either colour struggles.

Hex

#dd1133

RGB

221, 17, 51

OKLCh

57.1% 0.224 22.4°

CIELAB (D50)

47.9, 71.7, 40.9

What is true of this colour, and of no other

  • 4 other named colours sit within ΔE00 2 of it.
  • It uses 97% of the chroma sRGB can show at this lightness and hue — close enough to the boundary that a wider display would show it slightly more vividly.
  • As text on white it measures APCA Lc 72.1; on black, Lc -29.5. 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 39.1 and 46.9 and 53.5 — no red cone.

Text on this colour

White text

5.00:1 — passes AA

Black text

4.20:1 — large text only

White text is the better of the two at5.00:1. That is enough for body text.

The same colour, with one cone missing

As you see it

#dd1133

protanopia

#535335 · ΔE00 39.1

deuteranopia

#808023 · ΔE00 46.9

tritanopia

#a2a200 · ΔE00 53.5

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isRed Hot at ΔE00 0.798: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.

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