#043F64
Closest named color: Marine Blue (#01386A). oklch(35.4% 0.084 243.9), rgb(4, 63, 100).
Aa
White text reads best on this color (11.05:1).
About this color
#043F64 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.084 and its hue 244°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.026 away. White text reads best on it, at 11.05:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.084) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.90:1 |
| White text | 11.05:1 |
Values
| HEX | #043F64 |
| RGB | rgb(4, 63, 100) |
| HSL | hsl(203, 92%, 20%) |
| OKLCH | oklch(35.4% 0.084 243.9) |
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 #043F64 | 11.05:1 | AAA | Lc -99.0 | Preferred for body text |
| Black text on #043F64 | 1.90:1 | Fails | Lc 8.8 | Not readable |
| #043F64 text on white | 11.05:1 | AAA | Lc 95.1 | Preferred for body text |
| #043F64 text on black | 1.90:1 | Fails | Lc -7.5 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E0ECF5
oklch(93.7% 0.018 240)
-
Step 200
200
#C6DCEF
oklch(88.4% 0.035 244.2)
-
Step 300
300
#9EC6E7
oklch(80.9% 0.063 243.5)
-
Step 400
400
#66A7DB
oklch(70.6% 0.102 244.1)
-
Step 500
500
#3690D1
oklch(63% 0.129 244.1)
-
Step 600
600
#0079BD
oklch(55.5% 0.138 244.2)
-
Step 700
700
#0066A0
oklch(49.2% 0.121 244)
-
Step 800
800
#005384
oklch(42.6% 0.106 244.3)
-
Step 900
900 (this color)
#043F64
oklch(35.4% 0.084 243.9)
-
Step 950
950
#0B293E
oklch(27% 0.053 242.9)
#043F64 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) | #2D4066 | 0.036 |
| Deuteranopia (no green cones) | #203863 | 0.027 |
| Tritanopia (no blue cones) | #00484C | 0.058 |
| Achromatopsia (no color) | #3C3C3C | 0.084 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #043F64
#043F64
oklch(35.4% 0.084 243.9)
- #583100
#583100
oklch(35.5% 0.08 64.1)
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 #043F64, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.026
- Prussian Blue #1D3557 ΔE 0.036
- Twilight Blue #0A437A ΔE 0.039
- Dark Blue Grey #1F3B4D ΔE 0.041
- Midnight Green #073B4C ΔE 0.042
- Dark Grey Blue #29465B ΔE 0.044
- Charcoal #264653 ΔE 0.049
- Marine #042E60 ΔE 0.053
Use #043F64 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.