HueComb

Trial by Fire

#ef3939

A red that is saturated. It is light — black text sits on it comfortably, white text does not.

Hex

#ef3939

RGB

239, 57, 57

OKLCh

62.6% 0.218 26.2°

CIELAB (D50)

54.4, 68.7, 45.5

What is true of this colour, and of no other

  • 4 other named colours sit within ΔE00 2 of it.
  • It uses 86% 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 65.3; on black, Lc -36.4. 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 40.3 and 46.0 and 51.8 — no red cone.

Text on this colour

White text

3.95:1 — large text only

Black text

5.31:1 — passes AA

Black text is the better of the two at5.31:1. That is enough for body text.

As text on white, it needs to change

#e32b2f is the nearest colour of the same hue that passes AA on white, at 4.50:1. Only the lightness moved.

Try it against your own background

The same colour, with one cone missing

As you see it

#ef3939

protanopia

#66663b · ΔE00 40.3

deuteranopia

#919129 · ΔE00 46.0

tritanopia

#b2b200 · ΔE00 51.8

Run a whole palette through all three

The twelve nearest named colours

Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isSparkling Red at ΔE00 1.147: between 1 and 2 — a trained eye spots it when the two touch; nobody spots it across a room. What the numbers mean.

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