#003773
Closest named color: Marine Blue (#01386A). oklch(34.4% 0.116 255.6), rgb(0, 55, 115).
Aa
White text reads best on this color (11.70:1).
About this color
#003773 is a dark, moderately saturated blue. In OKLCH its lightness is 34%, its chroma 0.116 and its hue 256°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.016 away. White text reads best on it, at 11.70:1.
| Hue family | Blues |
| Lightness | dark (34%) |
| Chroma | moderately saturated (0.116) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.79:1 |
| White text | 11.70:1 |
Values
| HEX | #003773 |
| RGB | rgb(0, 55, 115) |
| HSL | hsl(211, 100%, 23%) |
| OKLCH | oklch(34.4% 0.116 255.6) |
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 #003773 | 11.70:1 | AAA | Lc -100.0 | Preferred for body text |
| Black text on #003773 | 1.79:1 | Fails | Lc 7.6 | Not readable |
| #003773 text on white | 11.70:1 | AAA | Lc 96.2 | Preferred for body text |
| #003773 text on black | 1.79:1 | 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
#F0F6FD
oklch(97.1% 0.011 252.1)
-
Step 100
100
#DFEBFB
oklch(93.6% 0.025 255.6)
-
Step 200
200
#C5DBF9
oklch(88.5% 0.048 256.2)
-
Step 300
300
#9BC3F9
oklch(80.8% 0.088 256.1)
-
Step 400
400
#63A2F5
oklch(70.6% 0.139 255.9)
-
Step 500
500
#3288F2
oklch(63% 0.179 255.9)
-
Step 600
600
#0070DD
oklch(55.6% 0.187 255.6)
-
Step 700
700
#005EBB
oklch(49.1% 0.165 255.5)
-
Step 800
800
#004C9B
oklch(42.6% 0.144 255.8)
-
Step 900
900 (this color)
#003773
oklch(34.4% 0.116 255.6)
-
Step 950
950
#0A2649
oklch(26.9% 0.073 255.8)
#003773 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) | #103D75 | 0.022 |
| Deuteranopia (no green cones) | #003472 | 0.009 |
| Tritanopia (no blue cones) | #00464F | 0.087 |
| Achromatopsia (no color) | #383838 | 0.116 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #003773
#003773
oklch(34.4% 0.116 255.6)
- #4E3300
#4E3300
oklch(34.4% 0.072 76.4)
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 #003773, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.016
- Twilight Blue #0A437A ΔE 0.038
- Marine #042E60 ΔE 0.041
- Prussian Blue #1D3557 ΔE 0.051
- Cobalt #1E488F ΔE 0.072
- Midnight Green #073B4C ΔE 0.073
- Dark Blue Grey #1F3B4D ΔE 0.073
- Midnight Blue #191970 ΔE 0.073
Use #003773 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.