#181521
Closest named color: Rich Black (#0D1B2A). oklch(20.5% 0.024 295.7), rgb(24, 21, 33).
Aa
White text reads best on this color (17.97:1).
About this color
#181521 is a very dark close to neutral grey. In OKLCH its lightness is 21%, its chroma 0.024. It has too little chroma to lean warm or cool. The nearest named color is Rich Black (#0D1B2A), ΔE 0.028 away. White text reads best on it, at 17.97:1.
| Hue family | Neutrals |
| Lightness | very dark (21%) |
| Chroma | close to neutral grey (0.024) |
| Temperature | neutral |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.16:1 |
| White text | 17.97:1 |
Values
| HEX | #181521 |
| RGB | rgb(24, 21, 33) |
| HSL | hsl(255, 22%, 11%) |
| OKLCH | oklch(20.5% 0.024 295.7) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #181521 | 17.97:1 | AAA | Lc -106.9 | Preferred for body text |
| Black text on #181521 | 1.16:1 | Fails | Lc 0.0 | Not readable |
| #181521 text on white | 17.97:1 | AAA | Lc 104.7 | Preferred for body text |
| #181521 text on black | 1.16:1 | Fails | Lc 0.0 | Not readable |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 950.
-
Step 50
50
#F5F5F8
oklch(97.1% 0.004 286.3)
-
Step 100
100
#EAE9EF
oklch(93.7% 0.008 293.9)
-
Step 200
200
#DAD7E3
oklch(88.5% 0.017 297.5)
-
Step 300
300
#C2BDD1
oklch(80.9% 0.028 297.2)
-
Step 400
400
#A29BBA
oklch(70.6% 0.045 295.6)
-
Step 500
500
#8C83A9
oklch(63.2% 0.057 295.6)
-
Step 600
600
#766C95
oklch(55.6% 0.064 295.4)
-
Step 700
700
#635A7F
oklch(49.1% 0.059 295.3)
-
Step 800
800
#514A67
oklch(42.8% 0.048 295.4)
-
Step 900
900
#433E54
oklch(37.8% 0.038 295)
-
Step 950
950 (this color)
#181521
oklch(20.5% 0.024 295.7)
#181521 with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #121722 | 0.012 |
| Deuteranopia (no green cones) | #131721 | 0.011 |
| Tritanopia (no blue cones) | #161719 | 0.020 |
| Achromatopsia (no color) | #171717 | 0.024 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #181521
#181521
oklch(20.5% 0.024 295.7)
- #17190C
#17190C
oklch(20.7% 0.024 115.7)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #181521, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.028
- Rich Navy #001219 ΔE 0.049
- Dark #1B2431 ΔE 0.055
- Almost Black #070D0D ΔE 0.059
- Jet #212529 ΔE 0.060
- Oxford Blue #1B263B ΔE 0.069
- Very Dark Purple #2A0134 ΔE 0.077
- Midnight Purple #280137 ΔE 0.079
Use #181521 in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.