#143F8C
Closest named color: Cobalt (#1E488F). oklch(38.8% 0.137 261), rgb(20, 63, 140).
Aa
White text reads best on this color (9.90:1).
About this color
#143F8C is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.137 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.028 away. White text reads best on it, at 9.90:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.137) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.11:1 |
| White text | 9.90:1 |
Values
| HEX | #143F8C |
| RGB | rgb(20, 63, 140) |
| HSL | hsl(218, 75%, 31%) |
| OKLCH | oklch(38.8% 0.137 261) |
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 #143F8C | 9.90:1 | AAA | Lc -96.7 | Preferred for body text |
| Black text on #143F8C | 2.11:1 | Fails | Lc 11.5 | Not readable |
| #143F8C text on white | 9.90:1 | AAA | Lc 92.4 | Preferred for body text |
| #143F8C text on black | 2.11:1 | Fails | Lc -10.0 | 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
#F0F6FF
oklch(97.1% 0.014 258.3)
-
Step 100
100
#DFEBFE
oklch(93.7% 0.029 259.6)
-
Step 200
200
#C5DAFF
oklch(88.5% 0.056 261.8)
-
Step 300
300
#9EC1FF
oklch(80.8% 0.096 261.6)
-
Step 400
400
#689FFF
oklch(70.7% 0.153 260.8)
-
Step 500
500
#3D82FF
oklch(63% 0.199 261.1)
-
Step 600
600
#1066F5
oklch(55.6% 0.227 260.9)
-
Step 700
700
#0153D6
oklch(49.1% 0.212 261.1)
-
Step 800
800
#0845AD
oklch(42.7% 0.176 261.1)
-
Step 900
900 (this color)
#143F8C
oklch(38.8% 0.137 261)
-
Step 950
950
#0B2450
oklch(27% 0.087 260.8)
#143F8C 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) | #00498F | 0.027 |
| Deuteranopia (no green cones) | #003E8A | 0.012 |
| Tritanopia (no blue cones) | #00525F | 0.105 |
| Achromatopsia (no color) | #434343 | 0.137 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #143F8C
#143F8C
oklch(38.8% 0.137 261)
- #5A3F00
#5A3F00
oklch(38.8% 0.08 81.1)
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 #143F8C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.028
- Twilight Blue #0A437A ΔE 0.034
- Light Navy #155084 ΔE 0.053
- Sapphire #2138AB ΔE 0.054
- Dusk Blue #26538D ΔE 0.062
- Marine Blue #01386A ΔE 0.063
- Blueberry #464196 ΔE 0.063
- Dark Slate Blue #483D8B ΔE 0.064
Use #143F8C 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.