#181D3B
Closest named color: Oxford Blue (#1B263B). oklch(24.3% 0.057 274.2), rgb(24, 29, 59).
Aa
White text reads best on this color (16.43:1).
About this color
#181D3B is a very dark, muted blue. In OKLCH its lightness is 24%, its chroma 0.057 and its hue 274°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.031 away. White text reads best on it, at 16.43:1.
| Hue family | Blues |
| Lightness | very dark (24%) |
| Chroma | muted (0.057) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.27:1 |
| White text | 16.43:1 |
Values
| HEX | #181D3B |
| RGB | rgb(24, 29, 59) |
| HSL | hsl(231, 42%, 16%) |
| OKLCH | oklch(24.3% 0.057 274.2) |
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 #181D3B | 16.43:1 | AAA | Lc -105.8 | Preferred for body text |
| Black text on #181D3B | 1.27:1 | Fails | Lc 0.0 | Not readable |
| #181D3B text on white | 16.43:1 | AAA | Lc 103.3 | Preferred for body text |
| #181D3B text on black | 1.27:1 | 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
#F3F5FC
oklch(97.1% 0.01 273.4)
-
Step 100
100
#E5E9F7
oklch(93.5% 0.019 273.2)
-
Step 200
200
#D1D8F3
oklch(88.5% 0.038 274.1)
-
Step 300
300
#B3BEED
oklch(80.9% 0.068 274.5)
-
Step 400
400
#8C9BE4
oklch(70.7% 0.108 274.4)
-
Step 500
500
#7181DD
oklch(63.2% 0.139 274.3)
-
Step 600
600
#5A68CA
oklch(55.5% 0.151 274.3)
-
Step 700
700
#4A56AF
oklch(49.1% 0.141 274.2)
-
Step 800
800
#3D478E
oklch(42.8% 0.117 274.4)
-
Step 900
900
#333C71
oklch(37.6% 0.091 274)
-
Step 950
950 (this color)
#181D3B
oklch(24.3% 0.057 274.2)
#181D3B 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) | #10213C | 0.016 |
| Deuteranopia (no green cones) | #0D1E3A | 0.016 |
| Tritanopia (no blue cones) | #092329 | 0.049 |
| Achromatopsia (no color) | #1F1F1F | 0.057 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #181D3B
#181D3B
oklch(24.3% 0.057 274.2)
- #281F00
#281F00
oklch(24.3% 0.05 93.2)
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 #181D3B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.031
- Dark #1B2431 ΔE 0.035
- Rich Black #0D1B2A ΔE 0.038
- Jet #212529 ΔE 0.052
- Navy Blue #001146 ΔE 0.058
- Space Cadet #2B2D42 ΔE 0.065
- Dark Indigo #1F0954 ΔE 0.067
- Midnight Purple #280137 ΔE 0.076
Use #181D3B 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.