#043F6F
Closest named color: Twilight Blue (#0A437A). oklch(36.2% 0.099 250.1), rgb(4, 63, 111).
Aa
White text reads best on this color (10.79:1).
About this color
#043F6F is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.099 and its hue 250°. 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 10.79:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.099) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.94:1 |
| White text | 10.79:1 |
Values
| HEX | #043F6F |
| RGB | rgb(4, 63, 111) |
| HSL | hsl(207, 93%, 23%) |
| OKLCH | oklch(36.2% 0.099 250.1) |
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 #043F6F | 10.79:1 | AAA | Lc -98.5 | Preferred for body text |
| Black text on #043F6F | 1.94:1 | Fails | Lc 9.4 | Not readable |
| #043F6F text on white | 10.79:1 | AAA | Lc 94.5 | Preferred for body text |
| #043F6F text on black | 1.94:1 | Fails | Lc -8.1 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#DFEBF8
oklch(93.5% 0.022 250.2)
-
Step 200
200
#C5DCF4
oklch(88.5% 0.041 249.4)
-
Step 300
300
#9CC5F0
oklch(80.9% 0.075 250)
-
Step 400
400
#64A5E8
oklch(70.6% 0.119 250.5)
-
Step 500
500
#318DE1
oklch(63.1% 0.152 250.1)
-
Step 600
600
#0076CB
oklch(55.7% 0.158 250)
-
Step 700
700
#0063AB
oklch(49.2% 0.138 249.7)
-
Step 800
800
#00518E
oklch(42.8% 0.121 249.9)
-
Step 900
900 (this color)
#043F6F
oklch(36.2% 0.099 250.1)
-
Step 950
950
#0A2844
oklch(27.1% 0.063 250.1)
#043F6F 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) | #274271 | 0.030 |
| Deuteranopia (no green cones) | #14396E | 0.018 |
| Tritanopia (no blue cones) | #004B51 | 0.073 |
| Achromatopsia (no color) | #3D3D3D | 0.099 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #043F6F
#043F6F
oklch(36.2% 0.099 250.1)
- #573500
#573500
oklch(36.2% 0.078 70.4)
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 #043F6F, 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 0.023
- Prussian Blue #1D3557 ΔE 0.048
- Dark Grey Blue #29465B ΔE 0.054
- Marine #042E60 ΔE 0.056
- Dark Blue Grey #1F3B4D ΔE 0.059
- Light Navy #155084 ΔE 0.061
- Midnight Green #073B4C ΔE 0.061
Use #043F6F 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.