#183A6E
Closest named color: Marine Blue (#01386A). oklch(35.4% 0.099 258.8), rgb(24, 58, 110).
Aa
White text reads best on this color (11.23:1).
About this color
#183A6E is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.099 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.019 away. White text reads best on it, at 11.23:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.099) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.86:1 |
| White text | 11.23:1 |
Values
| HEX | #183A6E |
| RGB | rgb(24, 58, 110) |
| HSL | hsl(216, 64%, 26%) |
| OKLCH | oklch(35.4% 0.099 258.8) |
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 #183A6E | 11.23:1 | AAA | Lc -99.4 | Preferred for body text |
| Black text on #183A6E | 1.86:1 | Fails | Lc 8.3 | Not readable |
| #183A6E text on white | 11.23:1 | AAA | Lc 95.6 | Preferred for body text |
| #183A6E text on black | 1.86:1 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF9
oklch(93.7% 0.022 256.7)
-
Step 200
200
#C9DAF5
oklch(88.4% 0.042 259.6)
-
Step 300
300
#A4C2F1
oklch(80.8% 0.074 259.3)
-
Step 400
400
#73A1EA
oklch(70.6% 0.119 259.3)
-
Step 500
500
#4D88E3
oklch(63% 0.151 258.8)
-
Step 600
600
#3070D1
oklch(55.6% 0.164 258.8)
-
Step 700
700
#225DB5
oklch(49.1% 0.152 258.7)
-
Step 800
800
#1E4C93
oklch(42.6% 0.127 259.1)
-
Step 900
900 (this color)
#183A6E
oklch(35.4% 0.099 258.8)
-
Step 950
950
#122644
oklch(26.9% 0.062 258.3)
#183A6E 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) | #1F3F70 | 0.018 |
| Deuteranopia (no green cones) | #0E376D | 0.013 |
| Tritanopia (no blue cones) | #00464E | 0.077 |
| Achromatopsia (no color) | #3B3B3B | 0.099 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183A6E
#183A6E
oklch(35.4% 0.099 258.8)
- #503600
#503600
oklch(35.4% 0.074 78.8)
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 #183A6E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.019
- Twilight Blue #0A437A ΔE 0.031
- Prussian Blue #1D3557 ΔE 0.041
- Marine #042E60 ΔE 0.047
- Dark Blue Grey #1F3B4D ΔE 0.059
- Dark Grey Blue #29465B ΔE 0.059
- Midnight Green #073B4C ΔE 0.064
- Cobalt #1E488F ΔE 0.066
Use #183A6E 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.