#181D33
Closest named color: Rich Black (#0D1B2A). oklch(23.8% 0.043 273), rgb(24, 29, 51).
Aa
White text reads best on this color (16.63:1).
About this color
#181D33 is a very dark, muted blue. In OKLCH its lightness is 24%, its chroma 0.043 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.026 away. White text reads best on it, at 16.63:1.
| Hue family | Blues |
| Lightness | very dark (24%) |
| Chroma | muted (0.043) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.26:1 |
| White text | 16.63:1 |
Values
| HEX | #181D33 |
| RGB | rgb(24, 29, 51) |
| HSL | hsl(229, 36%, 15%) |
| OKLCH | oklch(23.8% 0.043 273) |
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 #181D33 | 16.63:1 | AAA | Lc -106.0 | Preferred for body text |
| Black text on #181D33 | 1.26:1 | Fails | Lc 0.0 | Not readable |
| #181D33 text on white | 16.63:1 | AAA | Lc 103.5 | Preferred for body text |
| #181D33 text on black | 1.26:1 | 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
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E6E9F4
oklch(93.5% 0.015 273.8)
-
Step 200
200
#D3D8EC
oklch(88.4% 0.028 274.6)
-
Step 300
300
#B5BFE2
oklch(80.8% 0.051 272.7)
-
Step 400
400
#909ED4
oklch(70.8% 0.081 273)
-
Step 500
500
#7585C8
oklch(63.2% 0.103 272.9)
-
Step 600
600
#5E6DB5
oklch(55.5% 0.113 273.3)
-
Step 700
700
#4D5B9C
oklch(49.1% 0.105 272.8)
-
Step 800
800
#3F4B7E
oklch(42.7% 0.086 272.3)
-
Step 900
900
#363F66
oklch(37.8% 0.068 272.9)
-
Step 950
950 (this color)
#181D33
oklch(23.8% 0.043 273)
#181D33 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) | #151F34 | 0.008 |
| Deuteranopia (no green cones) | #131D32 | 0.008 |
| Tritanopia (no blue cones) | #0F2225 | 0.039 |
| Achromatopsia (no color) | #1E1E1E | 0.043 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #181D33
#181D33
oklch(23.8% 0.043 273)
- #261E04
#261E04
oklch(23.8% 0.043 92.2)
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 #181D33, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.026
- Dark #1B2431 ΔE 0.027
- Oxford Blue #1B263B ΔE 0.032
- Jet #212529 ΔE 0.042
- Navy Blue #001146 ΔE 0.066
- Space Cadet #2B2D42 ΔE 0.068
- Rich Navy #001219 ΔE 0.076
- Gunmetal #293241 ΔE 0.079
Use #181D33 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.