#343F73
Closest named color: Twilight Blue (#0A437A). oklch(38.5% 0.089 272.6), rgb(52, 63, 115).
Aa
White text reads best on this color (9.97:1).
About this color
#343F73 is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.089 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.039 away. White text reads best on it, at 9.97:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.089) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.10:1 |
| White text | 9.97:1 |
Values
| HEX | #343F73 |
| RGB | rgb(52, 63, 115) |
| HSL | hsl(230, 38%, 33%) |
| OKLCH | oklch(38.5% 0.089 272.6) |
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 #343F73 | 9.97:1 | AAA | Lc -97.2 | Preferred for body text |
| Black text on #343F73 | 2.10:1 | Fails | Lc 10.9 | Not readable |
| #343F73 text on white | 9.97:1 | AAA | Lc 93.0 | Preferred for body text |
| #343F73 text on black | 2.10:1 | Fails | Lc -9.5 | 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
#F3F5FC
oklch(97.1% 0.01 273.4)
-
Step 100
100
#E5E9F7
oklch(93.5% 0.019 273.2)
-
Step 200
200
#D0D8F3
oklch(88.5% 0.038 272.5)
-
Step 300
300
#B2BFED
oklch(81% 0.067 272.5)
-
Step 400
400
#8A9CE4
oklch(70.7% 0.108 272.7)
-
Step 500
500
#6E82DC
oklch(63.2% 0.137 272.5)
-
Step 600
600
#5769C9
oklch(55.5% 0.149 272.7)
-
Step 700
700
#4857AE
oklch(49.1% 0.139 272.9)
-
Step 800
800
#3B488D
oklch(42.8% 0.114 272.7)
-
Step 900
900 (this color)
#343F73
oklch(38.5% 0.089 272.6)
-
Step 950
950
#1D2442
oklch(27% 0.057 272.2)
#343F73 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) | #294575 | 0.020 |
| Deuteranopia (no green cones) | #224072 | 0.022 |
| Tritanopia (no blue cones) | #174A53 | 0.079 |
| Achromatopsia (no color) | #424242 | 0.090 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #343F73
#343F73
oklch(38.5% 0.089 272.6)
- #534200
#534200
oklch(38.6% 0.079 92.2)
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 #343F73, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.039
- Dark Slate Blue #483D8B ΔE 0.052
- Cobalt #1E488F ΔE 0.053
- Dark Grey Blue #29465B ΔE 0.053
- Light Navy #155084 ΔE 0.056
- Marine Blue #01386A ΔE 0.058
- Prussian Blue #1D3557 ΔE 0.065
- Blueberry #464196 ΔE 0.065
Use #343F73 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.