#183381
Closest named color: Marine Blue (#01386A). oklch(35.4% 0.136 265.3), rgb(24, 51, 129).
Aa
White text reads best on this color (11.47:1).
About this color
#183381 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.136 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.046 away. White text reads best on it, at 11.47:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.136) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.82:1 |
| White text | 11.47:1 |
Values
| HEX | #183381 |
| RGB | rgb(24, 51, 129) |
| HSL | hsl(225, 69%, 30%) |
| OKLCH | oklch(35.4% 0.136 265.3) |
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 #183381 | 11.47:1 | AAA | Lc -99.7 | Preferred for body text |
| Black text on #183381 | 1.82:1 | Fails | Lc 8.0 | Not readable |
| #183381 text on white | 11.47:1 | AAA | Lc 95.9 | Preferred for body text |
| #183381 text on black | 1.82:1 | 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 900.
-
Step 50
50
#F1F6FF
oklch(97.2% 0.013 262.4)
-
Step 100
100
#E0EAFE
oklch(93.6% 0.029 264.4)
-
Step 200
200
#C7D9FF
oklch(88.4% 0.056 265.2)
-
Step 300
300
#A3C0FF
oklch(80.9% 0.095 265.2)
-
Step 400
400
#729CFF
oklch(70.6% 0.153 265.4)
-
Step 500
500
#4E7FFF
oklch(63% 0.198 265.3)
-
Step 600
600
#3162F5
oklch(55.6% 0.226 265.3)
-
Step 700
700
#2550D5
oklch(49.1% 0.209 265.3)
-
Step 800
800
#1F42AC
oklch(42.6% 0.174 265.3)
-
Step 900
900 (this color)
#183381
oklch(35.4% 0.136 265.3)
-
Step 950
950
#122350
oklch(27.1% 0.086 265.4)
#183381 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) | #003E84 | 0.030 |
| Deuteranopia (no green cones) | #00357F | 0.016 |
| Tritanopia (no blue cones) | #004754 | 0.107 |
| Achromatopsia (no color) | #393939 | 0.136 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183381
#183381
oklch(35.4% 0.136 265.3)
- #4D3800
#4D3800
oklch(35.5% 0.073 85)
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 #183381, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.046
- Twilight Blue #0A437A ΔE 0.047
- Cobalt #1E488F ΔE 0.062
- Marine #042E60 ΔE 0.062
- Royal #0C1793 ΔE 0.065
- Midnight Blue #191970 ΔE 0.069
- Sapphire #2138AB ΔE 0.072
- Prussian Blue #1D3557 ΔE 0.074
Use #183381 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.