#181B2B
Closest named color: Rich Black (#0D1B2A). oklch(22.7% 0.031 275.5), rgb(24, 27, 43).
Aa
White text reads best on this color (17.06:1).
About this color
#181B2B is a very dark, muted blue. In OKLCH its lightness is 23%, its chroma 0.031 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.017 away. White text reads best on it, at 17.06:1.
| Hue family | Blues |
| Lightness | very dark (23%) |
| Chroma | muted (0.031) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.23:1 |
| White text | 17.06:1 |
Values
| HEX | #181B2B |
| RGB | rgb(24, 27, 43) |
| HSL | hsl(231, 28%, 13%) |
| OKLCH | oklch(22.7% 0.031 275.5) |
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 #181B2B | 17.06:1 | AAA | Lc -106.3 | Preferred for body text |
| Black text on #181B2B | 1.23:1 | Fails | Lc 0.0 | Not readable |
| #181B2B text on white | 17.06:1 | AAA | Lc 104.0 | Preferred for body text |
| #181B2B text on black | 1.23:1 | 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
#F4F5F9
oklch(97.1% 0.005 275)
-
Step 100
100
#E8E9F1
oklch(93.6% 0.011 280.5)
-
Step 200
200
#D5D8E7
oklch(88.4% 0.021 276.9)
-
Step 300
300
#B9BFD9
oklch(80.8% 0.037 275.2)
-
Step 400
400
#969EC6
oklch(70.7% 0.059 276)
-
Step 500
500
#7C86B8
oklch(63.1% 0.076 275.3)
-
Step 600
600
#656FA4
oklch(55.6% 0.083 275.2)
-
Step 700
700
#545D8C
oklch(49.1% 0.076 275)
-
Step 800
800
#454C72
oklch(42.7% 0.064 275.4)
-
Step 900
900
#3A3F5C
oklch(37.6% 0.05 276.2)
-
Step 950
950 (this color)
#181B2B
oklch(22.7% 0.031 275.5)
#181B2B 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) | #161D2C | 0.007 |
| Deuteranopia (no green cones) | #151B2B | 0.005 |
| Tritanopia (no blue cones) | #131E21 | 0.027 |
| Achromatopsia (no color) | #1C1C1C | 0.031 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #181B2B
#181B2B
oklch(22.7% 0.031 275.5)
- #211C0A
#211C0A
oklch(22.7% 0.031 94.2)
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 #181B2B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.017
- Dark #1B2431 ΔE 0.032
- Jet #212529 ΔE 0.042
- Oxford Blue #1B263B ΔE 0.044
- Rich Navy #001219 ΔE 0.065
- Navy Blue #001146 ΔE 0.074
- Space Cadet #2B2D42 ΔE 0.078
- Very Dark Purple #2A0134 ΔE 0.081
Use #181B2B 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.