#3F4551Dark Crypt (#3F4551) is a grey neutral with an OKLCH hue of 264°, lightness 0.39 and chroma 0.022. In practice it behaves as a mid-weight working color for secondary surfaces and editorial blocks.
| HEX | #3F4551 |
|---|---|
| RGB | rgb(63, 69, 81) |
| HSL | hsl(220, 12%, 28%) |
| HSV | hsv(220, 22%, 32%) |
| CMYK | cmyk(22%, 15%, 0%, 68%) |
| CIE Lab | lab(29.2 0.6 -8) |
| OKLCH | oklch(0.390 0.022 264) |
Under warm 2700K interior light Dark Crypt shifts only faintly, with no single dominant change; in north-facing or shaded light it is virtually unchanged. Overall drift across common illuminants is small (max ΔE ≈ 1.1), so it is a lighting-stable choice.
#43434b — ΔE 1.1, shifts only faintly, with no single dominant change#42454f — ΔE 0.6, is virtually unchanged#3f4551 — ΔE 0.0, is virtually unchanged#3f4552 — ΔE 0.2, is virtually unchangedTest Dark Crypt in the color lighting simulator — sweep it through daylight, warm 2700K light, 4000K LED, and shade alongside the rest of your palette.
Against white it measures 9.63:1 and against black 2.18:1, so white text is the stronger pairing. That pairing passes WCAG AA for body text. Avoid black text on this color entirely.
One color explored: close hues with real lightness and chroma structure, so the palette is the anchor through value rather than a set of colors.
#959aa4 · #6f7580 · #3f4551 · #2c313c · #0f141c · #000103
The anchor's neighbours on the wheel — everything shares an undertone, so the chord carries color without anything having to be muted to get along.
#426c82 · #365879 · #3f4551 · #2f3058 · #2a1f42 · #210f2b
The mid-gap pairing — sage and mustard, terracotta and olive. A foil rotated 40–65° toward warm or cool: too far to be kin, too near to argue, carried by temperature and a deliberate value offset.
#c5b3cd · #899bc1 · #8f6f9b · #695a6f · #3f4551 · #1b2a4b
One deliberately opposed voice — a single restrained counterpoint across the wheel, or temperature against temperature where the anchor is too muted to carry a loud opposite.
#dbc18c · #78839a · #5d6370 · #3f4551 · #1e283d · #090f1b
The anchor as the only color in the room. True neutrals or complement-warmed near-neutrals let it stay dominant.
#f5f1ea · #a0a5ae · #605d58 · #3f4551 · #292e37 · #030200
This color as a ground rather than a subject — its own restraint held across a narrow value band, carrying one saturated voice from the opposite temperature.
#eff2f7 · #c6c9d0 · #3f4551 · #1f232c · #02040a · #eebc4d
The opposite hue on the perceptual wheel, tempered to field strength — warm/cool tension without vibration.
#f9f1e1 · #b6a27a · #715a27 · #3f4551 · #3c2a00 · #000008
The complement's two neighbours instead of the complement itself — strong contrast with a lower clash risk.
#f9f1e1 · #c39b81 · #5d622e · #3f4551 · #46240a · #010100
Three hues spaced evenly around the wheel; the anchor leads and the other two are held at supporting strength.
#ffedeb · #c89692 · #426942 · #3f4551 · #173618 · #050000
Two complementary pairs offset by 90° — the richest chord, kept usable by a strict lightness hierarchy.
#ffecf3 · #c495a7 · #715a27 · #3f4551 · #00372c · #0e0600
#5A5F6B · #767B85 · #9498A1 · #B3B6BE · #D2D5DB
#343A44 · #2A2F38 · #20242C · #161A21 · #0D1016
Its moderate chroma lets it work in mid-size areas — upholstery, secondary UI surfaces, editorial blocks — without overwhelming neighbors. In palettes it pairs most predictably with its tonal ramp and analogous neighbors; reserve the complementary hue for small, deliberate contrast.