#18377B
Closest named color: Marine Blue (#01386A). oklch(35.7% 0.122 263.2), rgb(24, 55, 123).
Aa
White text reads best on this color (11.22:1).
About this color
#18377B is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.122 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.034 away. White text reads best on it, at 11.22:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.122) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.87:1 |
| White text | 11.22:1 |
Values
| HEX | #18377B |
| RGB | rgb(24, 55, 123) |
| HSL | hsl(221, 67%, 29%) |
| OKLCH | oklch(35.7% 0.122 263.2) |
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 #18377B | 11.22:1 | AAA | Lc -99.3 | Preferred for body text |
| Black text on #18377B | 1.87:1 | Fails | Lc 8.4 | Not readable |
| #18377B text on white | 11.22:1 | AAA | Lc 95.5 | Preferred for body text |
| #18377B 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E1EAFC
oklch(93.6% 0.026 264.4)
-
Step 200
200
#C8DAFC
oklch(88.6% 0.051 263.2)
-
Step 300
300
#A2C1FC
oklch(80.9% 0.091 263)
-
Step 400
400
#709EFB
oklch(70.7% 0.146 263.2)
-
Step 500
500
#4B82F9
oklch(63.1% 0.187 263.4)
-
Step 600
600
#2F68E8
oklch(55.6% 0.203 263.2)
-
Step 700
700
#2255C9
oklch(49% 0.189 263.2)
-
Step 800
800
#1D47A3
oklch(42.7% 0.156 263)
-
Step 900
900 (this color)
#18377B
oklch(35.7% 0.122 263.2)
-
Step 950
950
#11244C
oklch(27% 0.078 263.1)
#18377B 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) | #03407D | 0.026 |
| Deuteranopia (no green cones) | #00377A | 0.015 |
| Tritanopia (no blue cones) | #004853 | 0.096 |
| Achromatopsia (no color) | #3B3B3B | 0.122 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #18377B
#18377B
oklch(35.7% 0.122 263.2)
- #4F3800
#4F3800
oklch(35.7% 0.073 82.8)
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 #18377B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.034
- Twilight Blue #0A437A ΔE 0.034
- Marine #042E60 ΔE 0.057
- Cobalt #1E488F ΔE 0.057
- Prussian Blue #1D3557 ΔE 0.062
- Light Navy #155084 ΔE 0.073
- Dark Slate Blue #483D8B ΔE 0.075
- Midnight Blue #191970 ΔE 0.076
Use #18377B 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.