#373F69
Closest named color: Dark Grey Blue (#29465B). oklch(38.1% 0.072 274.3), rgb(55, 63, 105).
Aa
White text reads best on this color (10.10:1).
About this color
#373F69 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.072 and its hue 274°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.041 away. White text reads best on it, at 10.10:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.072) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 2.07:1 |
| White text | 10.10:1 |
Values
| HEX | #373F69 |
| RGB | rgb(55, 63, 105) |
| HSL | hsl(230, 31%, 31%) |
| OKLCH | oklch(38.1% 0.072 274.3) |
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 #373F69 | 10.10:1 | AAA | Lc -97.5 | Preferred for body text |
| Black text on #373F69 | 2.07:1 | Fails | Lc 10.5 | Not readable |
| #373F69 text on white | 10.10:1 | AAA | Lc 93.4 | Preferred for body text |
| #373F69 text on black | 2.07:1 | Fails | Lc -9.1 | 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
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E6E9F5
oklch(93.5% 0.016 274.8)
-
Step 200
200
#D3D8EE
oklch(88.5% 0.031 275.6)
-
Step 300
300
#B5BFE4
oklch(80.9% 0.053 273.3)
-
Step 400
400
#909DD7
oklch(70.8% 0.086 274.3)
-
Step 500
500
#7584CC
oklch(63.2% 0.11 273.9)
-
Step 600
600
#5E6CB9
oklch(55.6% 0.12 274.1)
-
Step 700
700
#4E5AA0
oklch(49.2% 0.112 274.2)
-
Step 800
800
#404A81
oklch(42.8% 0.092 274.1)
-
Step 900
900 (this color)
#373F69
oklch(38.1% 0.072 274.3)
-
Step 950
950
#20243D
oklch(26.9% 0.047 275.9)
#373F69 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) | #30446B | 0.016 |
| Deuteranopia (no green cones) | #2B4068 | 0.017 |
| Tritanopia (no blue cones) | #25484F | 0.065 |
| Achromatopsia (no color) | #424242 | 0.072 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373F69
#373F69
oklch(38.1% 0.072 274.3)
- #4F420A
#4F420A
oklch(38.2% 0.073 95)
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 #373F69, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.041
- Twilight Blue #0A437A ΔE 0.049
- Charcoal #264653 ΔE 0.054
- Prussian Blue #1D3557 ΔE 0.057
- Marine Blue #01386A ΔE 0.060
- Dark Blue Grey #1F3B4D ΔE 0.061
- Light Navy #155084 ΔE 0.064
- Dark Slate Blue #483D8B ΔE 0.065
Use #373F69 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.