#181D40
Closest named color: Oxford Blue (#1B263B). oklch(24.7% 0.066 274.4), rgb(24, 29, 64).
Aa
White text reads best on this color (16.29:1).
About this color
#181D40 is a very dark, muted blue. In OKLCH its lightness is 25%, its chroma 0.066 and its hue 274°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.034 away. White text reads best on it, at 16.29:1.
| Hue family | Blues |
| Lightness | very dark (25%) |
| Chroma | muted (0.066) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.28:1 |
| White text | 16.29:1 |
Values
| HEX | #181D40 |
| RGB | rgb(24, 29, 64) |
| HSL | hsl(233, 45%, 17%) |
| OKLCH | oklch(24.7% 0.066 274.4) |
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 #181D40 | 16.29:1 | AAA | Lc -105.7 | Preferred for body text |
| Black text on #181D40 | 1.28:1 | Fails | Lc 0.0 | Not readable |
| #181D40 text on white | 16.29:1 | AAA | Lc 103.1 | Preferred for body text |
| #181D40 text on black | 1.28:1 | 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
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E5E9FA
oklch(93.6% 0.023 275.4)
-
Step 200
200
#D0D8F7
oklch(88.6% 0.044 274)
-
Step 300
300
#B1BDF4
oklch(80.8% 0.079 274.9)
-
Step 400
400
#899AEE
oklch(70.8% 0.124 274.1)
-
Step 500
500
#6E7EE9
oklch(63.1% 0.16 274.5)
-
Step 600
600
#5864D7
oklch(55.5% 0.175 274.7)
-
Step 700
700
#4853BA
oklch(49.1% 0.161 274.3)
-
Step 800
800
#3B4497
oklch(42.7% 0.135 274.5)
-
Step 900
900
#323A78
oklch(37.6% 0.105 274.7)
-
Step 950
950 (this color)
#181D40
oklch(24.7% 0.066 274.4)
#181D40 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) | #0C2241 | 0.020 |
| Deuteranopia (no green cones) | #071E3F | 0.022 |
| Tritanopia (no blue cones) | #04252B | 0.059 |
| Achromatopsia (no color) | #202020 | 0.066 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #181D40
#181D40
oklch(24.7% 0.066 274.4)
- #292000
#292000
oklch(24.7% 0.051 93.6)
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 #181D40, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.034
- Dark #1B2431 ΔE 0.042
- Rich Black #0D1B2A ΔE 0.047
- Navy Blue #001146 ΔE 0.054
- Dark Indigo #1F0954 ΔE 0.059
- Jet #212529 ΔE 0.060
- Space Cadet #2B2D42 ΔE 0.064
- Marine #042E60 ΔE 0.073
Use #181D40 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.