#043C78
Closest named color: Twilight Blue (#0A437A). oklch(36.1% 0.116 255.2), rgb(4, 60, 120).
Aa
White text reads best on this color (10.92:1).
About this color
#043C78 is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.116 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.022 away. White text reads best on it, at 10.92:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.116) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.92:1 |
| White text | 10.92:1 |
Values
| HEX | #043C78 |
| RGB | rgb(4, 60, 120) |
| HSL | hsl(211, 94%, 24%) |
| OKLCH | oklch(36.1% 0.116 255.2) |
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 #043C78 | 10.92:1 | AAA | Lc -98.6 | Preferred for body text |
| Black text on #043C78 | 1.92:1 | Fails | Lc 9.2 | Not readable |
| #043C78 text on white | 10.92:1 | AAA | Lc 94.7 | Preferred for body text |
| #043C78 text on black | 1.92:1 | Fails | Lc -7.9 | 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
#C4DBF9
oklch(88.4% 0.048 255.1)
-
Step 300
300
#9BC4F8
oklch(81% 0.086 254.6)
-
Step 400
400
#62A3F5
oklch(70.8% 0.138 255)
-
Step 500
500
#3089F1
oklch(63.1% 0.177 255)
-
Step 600
600
#0070DB
oklch(55.5% 0.184 255.3)
-
Step 700
700
#005EBA
oklch(49.1% 0.163 255.3)
-
Step 800
800
#004D9A
oklch(42.7% 0.142 255.2)
-
Step 900
900 (this color)
#043C78
oklch(36.1% 0.116 255.2)
-
Step 950
950
#092649
oklch(26.9% 0.074 255.3)
#043C78 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) | #18427A | 0.023 |
| Deuteranopia (no green cones) | #003877 | 0.012 |
| Tritanopia (no blue cones) | #004B54 | 0.087 |
| Achromatopsia (no color) | #3D3D3D | 0.116 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #043C78
#043C78
oklch(36.1% 0.116 255.2)
- #543700
#543700
oklch(36.2% 0.076 76.1)
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 #043C78, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.022
- Marine Blue #01386A ΔE 0.026
- Cobalt #1E488F ΔE 0.055
- Marine #042E60 ΔE 0.057
- Prussian Blue #1D3557 ΔE 0.058
- Light Navy #155084 ΔE 0.063
- Dark Grey Blue #29465B ΔE 0.071
- Deep Sea Blue #015482 ΔE 0.072
Use #043C78 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.