Crucible
#555b59
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
#555b59
RGB
85, 91, 89
OKLCh
46.5% 0.008 174.1°
CIELAB (D50)
38.1, -2.8, 0.3
What is true of this colour, and of no other
- One other named colour sits within ΔE00 2 of it.
- It uses only 9% 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 84.0; on black, Lc -17.9. 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.
- tritanopia shifts it by ΔE00 10.9 — no blue cone.
Text on this colour
White text
6.94:1 — passes AA
Black text
3.03:1 — large text only
White text is the better of the two at6.94:1. That is enough for body text.
The same colour, with one cone missing
As you see it
#555b59
protanopia
#5a5a59 · ΔE00 3.5
deuteranopia
#595959 · ΔE00 3.8
tritanopia
#585869 · ΔE00 10.9
The twelve nearest named colours
Ranked by CIEDE2000 — perceptual distance, not hex arithmetic. The closest isCarbon Dating at ΔE00 0.753: below 1.0 — an ordinary observer cannot tell these apart, even side by side. What the numbers mean.
- Carbon DatingΔE00 0.753 · #565b58
- Mostly MetalΔE00 2.064 · #575e5f
- Black PoolΔE00 2.224 · #4f5552
- SootΔE00 2.326 · #555e5f
- Cape CodΔE00 2.374 · #4e5552
- MakoΔE00 2.415 · #505555
- ParamountΔE00 2.51 · #5b6161
- Zen RetreatΔE00 2.616 · #5b5d5c
- Pointed FirΔE00 2.779 · #575d56
- Muted EbonyΔE00 2.865 · #515453
- Sable CalmΔE00 2.907 · #505650
- Blackish GreenΔE00 2.934 · #5d6161
12 of these have no page of their own: pages exist for the 4,961 colours the dataset marks as good names.