#043D8C
Closest named color: Twilight Blue (#0A437A). oklch(38% 0.142 259), rgb(4, 61, 140).
Aa
White text reads best on this color (10.23:1).
About this color
#043D8C is a dark, vivid blue. In OKLCH its lightness is 38%, its chroma 0.142 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.036 away. White text reads best on it, at 10.23:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | vivid (0.142) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.05:1 |
| White text | 10.23:1 |
Values
| HEX | #043D8C |
| RGB | rgb(4, 61, 140) |
| HSL | hsl(215, 94%, 28%) |
| OKLCH | oklch(38% 0.142 259) |
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 #043D8C | 10.23:1 | AAA | Lc -97.2 | Preferred for body text |
| Black text on #043D8C | 2.05:1 | Fails | Lc 10.9 | Not readable |
| #043D8C text on white | 10.23:1 | AAA | Lc 93.0 | Preferred for body text |
| #043D8C text on black | 2.05:1 | Fails | Lc -9.4 | 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
#F0F6FF
oklch(97.1% 0.014 258.3)
-
Step 100
100
#DEEBFF
oklch(93.6% 0.031 258.9)
-
Step 200
200
#C3DBFF
oklch(88.5% 0.056 258.4)
-
Step 300
300
#9BC2FF
oklch(80.8% 0.097 259.2)
-
Step 400
400
#63A0FF
oklch(70.7% 0.154 259)
-
Step 500
500
#3384FF
oklch(63.1% 0.199 259)
-
Step 600
600
#006AEE
oklch(55.7% 0.215 258.9)
-
Step 700
700
#0058CA
oklch(49.1% 0.191 259.1)
-
Step 800
800
#0048A7
oklch(42.7% 0.165 259)
-
Step 900
900 (this color)
#043D8C
oklch(38% 0.142 259)
-
Step 950
950
#062451
oklch(26.9% 0.09 258.8)
#043D8C 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) | #00478F | 0.028 |
| Deuteranopia (no green cones) | #003B8A | 0.007 |
| Tritanopia (no blue cones) | #00515E | 0.108 |
| Achromatopsia (no color) | #414141 | 0.142 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #043D8C
#043D8C
oklch(38% 0.142 259)
- #593C00
#593C00
oklch(38% 0.079 78.1)
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 #043D8C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.036
- Cobalt #1E488F ΔE 0.037
- Sapphire #2138AB ΔE 0.056
- Marine Blue #01386A ΔE 0.059
- Light Navy #155084 ΔE 0.060
- Dusk Blue #26538D ΔE 0.071
- Deep Sea Blue #015482 ΔE 0.071
- Dark Slate Blue #483D8B ΔE 0.073
Use #043D8C 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.