#00387B
Closest named color: Marine Blue (#01386A). oklch(35.3% 0.126 257.1), rgb(0, 56, 123).
Aa
White text reads best on this color (11.34:1).
About this color
#00387B is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.126 and its hue 257°. 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 11.34:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.126) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.85:1 |
| White text | 11.34:1 |
Values
| HEX | #00387B |
| RGB | rgb(0, 56, 123) |
| HSL | hsl(213, 100%, 24%) |
| OKLCH | oklch(35.3% 0.126 257.1) |
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 #00387B | 11.34:1 | AAA | Lc -99.3 | Preferred for body text |
| Black text on #00387B | 1.85:1 | Fails | Lc 8.4 | Not readable |
| #00387B text on white | 11.34:1 | AAA | Lc 95.5 | Preferred for body text |
| #00387B text on black | 1.85:1 | 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
#F0F6FE
oklch(97.1% 0.012 255.5)
-
Step 100
100
#DFEBFD
oklch(93.6% 0.028 258.4)
-
Step 200
200
#C4DBFC
oklch(88.5% 0.052 257.4)
-
Step 300
300
#9AC3FE
oklch(80.9% 0.095 257.4)
-
Step 400
400
#60A1FD
oklch(70.7% 0.151 257.3)
-
Step 500
500
#2D86FB
oklch(63.1% 0.193 257.1)
-
Step 600
600
#006DE4
oklch(55.5% 0.199 257.3)
-
Step 700
700
#005CC1
oklch(49.2% 0.175 257.1)
-
Step 800
800
#004BA0
oklch(42.8% 0.152 257.1)
-
Step 900
900 (this color)
#00387B
oklch(35.3% 0.126 257.1)
-
Step 950
950
#08254C
oklch(26.8% 0.08 257.2)
#00387B 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 | 0.024 |
| Deuteranopia (no green cones) | #00357A | 0.009 |
| Tritanopia (no blue cones) | #004953 | 0.096 |
| Achromatopsia (no color) | #3A3A3A | 0.126 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #00387B
#00387B
oklch(35.3% 0.126 257.1)
- #513500
#513500
oklch(35.3% 0.074 76.2)
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 #00387B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.029
- Twilight Blue #0A437A ΔE 0.034
- Marine #042E60 ΔE 0.053
- Cobalt #1E488F ΔE 0.061
- Prussian Blue #1D3557 ΔE 0.063
- Light Navy #155084 ΔE 0.074
- Midnight Blue #191970 ΔE 0.077
- Royal #0C1793 ΔE 0.077
Use #00387B 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.