#043A73
Closest named color: Marine Blue (#01386A). oklch(35.2% 0.111 254.9), rgb(4, 58, 115).
Aa
White text reads best on this color (11.30:1).
About this color
#043A73 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.111 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.017 away. White text reads best on it, at 11.30:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.111) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.85:1 |
| White text | 11.30:1 |
Values
| HEX | #043A73 |
| RGB | rgb(4, 58, 115) |
| HSL | hsl(211, 93%, 23%) |
| OKLCH | oklch(35.2% 0.111 254.9) |
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 #043A73 | 11.30:1 | AAA | Lc -99.3 | Preferred for body text |
| Black text on #043A73 | 1.85:1 | Fails | Lc 8.4 | Not readable |
| #043A73 text on white | 11.30:1 | AAA | Lc 95.5 | Preferred for body text |
| #043A73 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#DFEBFA
oklch(93.6% 0.024 254)
-
Step 200
200
#C5DBF8
oklch(88.4% 0.047 255.4)
-
Step 300
300
#9CC4F6
oklch(80.9% 0.083 254.3)
-
Step 400
400
#64A3F2
oklch(70.7% 0.134 254.9)
-
Step 500
500
#3489ED
oklch(63% 0.171 254.9)
-
Step 600
600
#0071DA
oklch(55.6% 0.182 254.8)
-
Step 700
700
#005FB9
oklch(49.2% 0.161 254.8)
-
Step 800
800
#004D99
oklch(42.7% 0.14 255)
-
Step 900
900 (this color)
#043A73
oklch(35.2% 0.111 254.9)
-
Step 950
950
#0B2748
oklch(27.2% 0.07 254.7)
#043A73 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) | #193F75 | 0.022 |
| Deuteranopia (no green cones) | #003672 | 0.013 |
| Tritanopia (no blue cones) | #004851 | 0.082 |
| Achromatopsia (no color) | #3A3A3A | 0.111 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #043A73
#043A73
oklch(35.2% 0.111 254.9)
- #513400
#513400
oklch(35.1% 0.074 74.8)
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 #043A73, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.017
- Twilight Blue #0A437A ΔE 0.029
- Marine #042E60 ΔE 0.047
- Prussian Blue #1D3557 ΔE 0.050
- Cobalt #1E488F ΔE 0.065
- Dark Blue Grey #1F3B4D ΔE 0.069
- Dark Grey Blue #29465B ΔE 0.070
- Midnight Green #073B4C ΔE 0.070
Use #043A73 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.