#183B6B
Closest named color: Marine Blue (#01386A). oklch(35.4% 0.093 257.1), rgb(24, 59, 107).
Aa
White text reads best on this color (11.18:1).
About this color
#183B6B is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.093 and its hue 257°. 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 11.18:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.093) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.87:1 |
| White text | 11.18:1 |
Values
| HEX | #183B6B |
| RGB | rgb(24, 59, 107) |
| HSL | hsl(215, 63%, 26%) |
| OKLCH | oklch(35.4% 0.093 257.1) |
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 #183B6B | 11.18:1 | AAA | Lc -99.4 | Preferred for body text |
| Black text on #183B6B | 1.87:1 | Fails | Lc 8.3 | Not readable |
| #183B6B text on white | 11.18:1 | AAA | Lc 95.6 | Preferred for body text |
| #183B6B text on black | 1.87:1 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EBF8
oklch(93.7% 0.02 257.5)
-
Step 200
200
#C9DBF3
oklch(88.5% 0.038 255.6)
-
Step 300
300
#A4C3EE
oklch(80.9% 0.07 256.6)
-
Step 400
400
#73A2E5
oklch(70.6% 0.111 257.3)
-
Step 500
500
#4D8ADE
oklch(63.2% 0.142 256.9)
-
Step 600
600
#2F72CC
oklch(55.7% 0.155 257)
-
Step 700
700
#225FB0
oklch(49.2% 0.143 257)
-
Step 800
800
#1E4E8F
oklch(42.8% 0.119 257.1)
-
Step 900
900 (this color)
#183B6B
oklch(35.4% 0.093 257.1)
-
Step 950
950
#122743
oklch(27.1% 0.059 256.2)
#183B6B 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) | #243F6D | 0.019 |
| Deuteranopia (no green cones) | #15386A | 0.010 |
| Tritanopia (no blue cones) | #00464D | 0.072 |
| Achromatopsia (no color) | #3B3B3B | 0.093 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183B6B
#183B6B
oklch(35.4% 0.093 257.1)
- #513600
#513600
oklch(35.5% 0.074 77.7)
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 #183B6B, 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 0.032
- Prussian Blue #1D3557 ΔE 0.036
- Marine #042E60 ΔE 0.048
- Dark Blue Grey #1F3B4D ΔE 0.053
- Dark Grey Blue #29465B ΔE 0.054
- Midnight Green #073B4C ΔE 0.058
- Charcoal #264653 ΔE 0.063
Use #183B6B 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.