#18387B
Closest named color: Twilight Blue (#0A437A). oklch(35.9% 0.12 262.7), rgb(24, 56, 123).
Aa
White text reads best on this color (11.10:1).
About this color
#18387B is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.120 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.032 away. White text reads best on it, at 11.10:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.120) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.89:1 |
| White text | 11.10:1 |
Values
| HEX | #18387B |
| RGB | rgb(24, 56, 123) |
| HSL | hsl(221, 67%, 29%) |
| OKLCH | oklch(35.9% 0.12 262.7) |
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 #18387B | 11.10:1 | AAA | Lc -99.1 | Preferred for body text |
| Black text on #18387B | 1.89:1 | Fails | Lc 8.7 | Not readable |
| #18387B text on white | 11.10:1 | AAA | Lc 95.2 | Preferred for body text |
| #18387B text on black | 1.89:1 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E1EAFC
oklch(93.6% 0.026 264.4)
-
Step 200
200
#C8DAFB
oklch(88.5% 0.05 262.6)
-
Step 300
300
#A2C1FC
oklch(80.9% 0.091 263)
-
Step 400
400
#6F9EFA
oklch(70.6% 0.145 262.7)
-
Step 500
500
#4A83F7
oklch(63.1% 0.184 262.6)
-
Step 600
600
#2D69E6
oklch(55.6% 0.2 262.5)
-
Step 700
700
#2156C8
oklch(49% 0.186 262.8)
-
Step 800
800
#1D47A2
oklch(42.7% 0.155 262.9)
-
Step 900
900 (this color)
#18387B
oklch(35.9% 0.12 262.7)
-
Step 950
950
#11244B
oklch(26.9% 0.077 262.8)
#18387B 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) | #08407D | 0.023 |
| Deuteranopia (no green cones) | #00377A | 0.016 |
| Tritanopia (no blue cones) | #004854 | 0.093 |
| Achromatopsia (no color) | #3C3C3C | 0.121 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #18387B
#18387B
oklch(35.9% 0.12 262.7)
- #503900
#503900
oklch(36.1% 0.074 83.2)
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 #18387B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.032
- Marine Blue #01386A ΔE 0.034
- Cobalt #1E488F ΔE 0.055
- Marine #042E60 ΔE 0.058
- Prussian Blue #1D3557 ΔE 0.062
- Light Navy #155084 ΔE 0.070
- Dark Slate Blue #483D8B ΔE 0.074
- Midnight Blue #191970 ΔE 0.078
Use #18387B 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.