#181B39
Closest named color: Rich Black (#0D1B2A). oklch(23.7% 0.057 276.8), rgb(24, 27, 57).
Aa
White text reads best on this color (16.73:1).
About this color
#181B39 is a very dark, muted blue. In OKLCH its lightness is 24%, its chroma 0.057 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.035 away. White text reads best on it, at 16.73:1.
| Hue family | Blues |
| Lightness | very dark (24%) |
| Chroma | muted (0.057) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.25:1 |
| White text | 16.73:1 |
Values
| HEX | #181B39 |
| RGB | rgb(24, 27, 57) |
| HSL | hsl(235, 41%, 16%) |
| OKLCH | oklch(23.7% 0.057 276.8) |
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 #181B39 | 16.73:1 | AAA | Lc -106.0 | Preferred for body text |
| Black text on #181B39 | 1.25:1 | Fails | Lc 0.0 | Not readable |
| #181B39 text on white | 16.73:1 | AAA | Lc 103.6 | Preferred for body text |
| #181B39 text on black | 1.25:1 | 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
#F4F5FC
oklch(97.1% 0.009 279.7)
-
Step 100
100
#E6E9F7
oklch(93.6% 0.019 276.3)
-
Step 200
200
#D2D7F3
oklch(88.4% 0.039 277.6)
-
Step 300
300
#B5BDED
oklch(80.9% 0.068 277.4)
-
Step 400
400
#8F9AE4
oklch(70.7% 0.109 276.8)
-
Step 500
500
#757FDC
oklch(63% 0.139 277)
-
Step 600
600
#5F67C9
oklch(55.6% 0.15 276.9)
-
Step 700
700
#4E55AE
oklch(49.1% 0.14 276.6)
-
Step 800
800
#40468D
oklch(42.7% 0.116 276.7)
-
Step 900
900
#363B71
oklch(37.6% 0.092 277.1)
-
Step 950
950 (this color)
#181B39
oklch(23.7% 0.057 276.8)
#181B39 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) | #0E1F3A | 0.018 |
| Deuteranopia (no green cones) | #0B1C38 | 0.019 |
| Tritanopia (no blue cones) | #0B2127 | 0.049 |
| Achromatopsia (no color) | #1E1E1E | 0.057 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #181B39
#181B39
oklch(23.7% 0.057 276.8)
- #251E00
#251E00
oklch(23.6% 0.049 96.6)
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 #181B39, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.035
- Oxford Blue #1B263B ΔE 0.037
- Dark #1B2431 ΔE 0.038
- Jet #212529 ΔE 0.055
- Navy Blue #001146 ΔE 0.056
- Dark Indigo #1F0954 ΔE 0.066
- Space Cadet #2B2D42 ΔE 0.071
- Midnight Purple #280137 ΔE 0.071
Use #181B39 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.