#04377F
Closest named color: Marine Blue (#01386A). oklch(35.5% 0.132 259), rgb(4, 55, 127).
Aa
White text reads best on this color (11.30:1).
About this color
#04377F is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.132 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.037 away. White text reads best on it, at 11.30:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.132) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.85:1 |
| White text | 11.30:1 |
Values
| HEX | #04377F |
| RGB | rgb(4, 55, 127) |
| HSL | hsl(215, 94%, 26%) |
| OKLCH | oklch(35.5% 0.132 259) |
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 #04377F | 11.30:1 | AAA | Lc -99.2 | Preferred for body text |
| Black text on #04377F | 1.85:1 | Fails | Lc 8.5 | Not readable |
| #04377F text on white | 11.30:1 | AAA | Lc 95.4 | Preferred for body text |
| #04377F 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
#F0F6FF
oklch(97.1% 0.014 258.3)
-
Step 100
100
#DFEBFE
oklch(93.7% 0.029 259.6)
-
Step 200
200
#C4DBFE
oklch(88.6% 0.054 258.7)
-
Step 300
300
#9BC2FF
oklch(80.8% 0.097 259.2)
-
Step 400
400
#63A0FF
oklch(70.7% 0.154 259)
-
Step 500
500
#3384FF
oklch(63.1% 0.199 259)
-
Step 600
600
#006AEE
oklch(55.7% 0.215 258.9)
-
Step 700
700
#0058CA
oklch(49.1% 0.191 259.1)
-
Step 800
800
#0048A7
oklch(42.7% 0.165 259)
-
Step 900
900 (this color)
#04377F
oklch(35.5% 0.132 259)
-
Step 950
950
#09254E
oklch(27.1% 0.083 258.4)
#04377F 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) | #004082 | 0.025 |
| Deuteranopia (no green cones) | #00357E | 0.007 |
| Tritanopia (no blue cones) | #004955 | 0.100 |
| Achromatopsia (no color) | #3A3A3A | 0.132 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #04377F
#04377F
oklch(35.5% 0.132 259)
- #503600
#503600
oklch(35.4% 0.074 78.8)
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 #04377F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.037
- Twilight Blue #0A437A ΔE 0.037
- Marine #042E60 ΔE 0.059
- Cobalt #1E488F ΔE 0.059
- Prussian Blue #1D3557 ΔE 0.070
- Royal #0C1793 ΔE 0.071
- Light Navy #155084 ΔE 0.075
- Midnight Blue #191970 ΔE 0.076
Use #04377F 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.