#181F40
Closest named color: Oxford Blue (#1B263B). oklch(25.2% 0.063 272.2), rgb(24, 31, 64).
Aa
White text reads best on this color (16.04:1).
About this color
#181F40 is a dark, muted blue. In OKLCH its lightness is 25%, its chroma 0.063 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.028 away. White text reads best on it, at 16.04:1.
| Hue family | Blues |
| Lightness | dark (25%) |
| Chroma | muted (0.063) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.30:1 |
| White text | 16.04:1 |
Values
| HEX | #181F40 |
| RGB | rgb(24, 31, 64) |
| HSL | hsl(230, 45%, 17%) |
| OKLCH | oklch(25.2% 0.063 272.2) |
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 #181F40 | 16.04:1 | AAA | Lc -105.5 | Preferred for body text |
| Black text on #181F40 | 1.30:1 | Fails | Lc 0.0 | Not readable |
| #181F40 text on white | 16.04:1 | AAA | Lc 102.9 | Preferred for body text |
| #181F40 text on black | 1.30:1 | 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
#E5E9F9
oklch(93.6% 0.022 274.7)
-
Step 200
200
#CFD8F5
oklch(88.4% 0.041 271.9)
-
Step 300
300
#B0BEF2
oklch(80.9% 0.075 272.9)
-
Step 400
400
#879BEB
oklch(70.7% 0.12 272.3)
-
Step 500
500
#6B80E5
oklch(63.1% 0.153 272.5)
-
Step 600
600
#5467D3
oklch(55.6% 0.166 272.4)
-
Step 700
700
#4555B6
oklch(49% 0.153 272.4)
-
Step 800
800
#384694
oklch(42.7% 0.128 272.2)
-
Step 900
900
#303C76
oklch(37.8% 0.1 272)
-
Step 950
950 (this color)
#181F40
oklch(25.2% 0.063 272.2)
#181F40 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) | #102341 | 0.015 |
| Deuteranopia (no green cones) | #0B203F | 0.017 |
| Tritanopia (no blue cones) | #04262C | 0.055 |
| Achromatopsia (no color) | #212121 | 0.063 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #181F40
#181F40
oklch(25.2% 0.063 272.2)
- #2B2100
#2B2100
oklch(25.2% 0.052 92.1)
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 #181F40, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.028
- Dark #1B2431 ΔE 0.037
- Rich Black #0D1B2A ΔE 0.047
- Jet #212529 ΔE 0.055
- Space Cadet #2B2D42 ΔE 0.059
- Navy Blue #001146 ΔE 0.059
- Dark Indigo #1F0954 ΔE 0.064
- Marine #042E60 ΔE 0.069
Use #181F40 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.