#183E63
Closest named color: Marine Blue (#01386A). oklch(35.6% 0.078 250.4), rgb(24, 62, 99).
Aa
White text reads best on this color (11.00:1).
About this color
#183E63 is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.078 and its hue 250°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.029 away. White text reads best on it, at 11.00:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.078) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.90:1 |
| White text | 11.00:1 |
Values
| HEX | #183E63 |
| RGB | rgb(24, 62, 99) |
| HSL | hsl(210, 61%, 24%) |
| OKLCH | oklch(35.6% 0.078 250.4) |
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 #183E63 | 11.00:1 | AAA | Lc -99.1 | Preferred for body text |
| Black text on #183E63 | 1.90:1 | Fails | Lc 8.7 | Not readable |
| #183E63 text on white | 11.00:1 | AAA | Lc 95.2 | Preferred for body text |
| #183E63 text on black | 1.90:1 | Fails | Lc -7.4 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E2EBF5
oklch(93.6% 0.017 250.8)
-
Step 200
200
#CADBEE
oklch(88.5% 0.032 251.1)
-
Step 300
300
#A5C4E6
oklch(80.9% 0.059 250.9)
-
Step 400
400
#73A5D9
oklch(70.7% 0.093 250.2)
-
Step 500
500
#4D8DCF
oklch(63% 0.12 250.9)
-
Step 600
600
#2E76BC
oklch(55.6% 0.13 250.9)
-
Step 700
700
#2063A2
oklch(49.1% 0.121 250.7)
-
Step 800
800
#1D5183
oklch(42.7% 0.1 250.7)
-
Step 900
900 (this color)
#183E63
oklch(35.6% 0.078 250.4)
-
Step 950
950
#12283E
oklch(27.1% 0.05 250.2)
#183E63 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) | #2D4065 | 0.025 |
| Deuteranopia (no green cones) | #223962 | 0.017 |
| Tritanopia (no blue cones) | #00474B | 0.060 |
| Achromatopsia (no color) | #3C3C3C | 0.078 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183E63
#183E63
oklch(35.6% 0.078 250.4)
- #553400
#553400
oklch(35.7% 0.077 70.8)
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 #183E63, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.029
- Prussian Blue #1D3557 ΔE 0.032
- Dark Blue Grey #1F3B4D ΔE 0.038
- Dark Grey Blue #29465B ΔE 0.038
- Twilight Blue #0A437A ΔE 0.040
- Midnight Green #073B4C ΔE 0.044
- Charcoal #264653 ΔE 0.046
- Marine #042E60 ΔE 0.055
Use #183E63 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.