#043C5B
Closest named color: Prussian Blue (#1D3557). oklch(34% 0.076 240.5), rgb(4, 60, 91).
Aa
White text reads best on this color (11.65:1).
About this color
#043C5B is a dark, moderately saturated blue. In OKLCH its lightness is 34%, its chroma 0.076 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.026 away. White text reads best on it, at 11.65:1.
| Hue family | Blues |
| Lightness | dark (34%) |
| Chroma | moderately saturated (0.076) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.80:1 |
| White text | 11.65:1 |
Values
| HEX | #043C5B |
| RGB | rgb(4, 60, 91) |
| HSL | hsl(201, 92%, 19%) |
| OKLCH | oklch(34% 0.076 240.5) |
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 #043C5B | 11.65:1 | AAA | Lc -100.1 | Preferred for body text |
| Black text on #043C5B | 1.80:1 | Fails | Lc 7.5 | Not readable |
| #043C5B text on white | 11.65:1 | AAA | Lc 96.4 | Preferred for body text |
| #043C5B text on black | 1.80:1 | 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
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E1ECF4
oklch(93.7% 0.016 239.1)
-
Step 200
200
#C7DCEC
oklch(88.4% 0.032 240.7)
-
Step 300
300
#A0C6E2
oklch(80.8% 0.057 240.3)
-
Step 400
400
#6AA8D4
oklch(70.7% 0.091 240.7)
-
Step 500
500
#3C92C9
oklch(63.2% 0.116 240.4)
-
Step 600
600
#087BB5
oklch(55.6% 0.126 240.2)
-
Step 700
700
#00679A
oklch(49.1% 0.113 240.5)
-
Step 800
800
#03547F
oklch(42.6% 0.098 241.1)
-
Step 900
900 (this color)
#043C5B
oklch(34% 0.076 240.5)
-
Step 950
950
#0D293C
oklch(27% 0.049 241.5)
#043C5B 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) | #2D3D5C | 0.038 |
| Deuteranopia (no green cones) | #21355A | 0.029 |
| Tritanopia (no blue cones) | #004447 | 0.051 |
| Achromatopsia (no color) | #383838 | 0.076 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #043C5B
#043C5B
oklch(34% 0.076 240.5)
- #542D04
#542D04
oklch(34.1% 0.076 60.2)
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 #043C5B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.026
- Midnight Green #073B4C ΔE 0.026
- Dark Blue Grey #1F3B4D ΔE 0.029
- Marine Blue #01386A ΔE 0.032
- Marine #042E60 ΔE 0.047
- Dark Grey Blue #29465B ΔE 0.048
- Charcoal #264653 ΔE 0.050
- Gunmetal #293241 ΔE 0.055
Use #043C5B 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.