#373B68
Closest named color: Dark Grey Blue (#29465B). oklch(37.1% 0.077 278.1), rgb(55, 59, 104).
Aa
White text reads best on this color (10.56:1).
About this color
#373B68 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.077 and its hue 278°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.048 away. White text reads best on it, at 10.56:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.077) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 1.98:1 |
| White text | 10.56:1 |
Values
| HEX | #373B68 |
| RGB | rgb(55, 59, 104) |
| HSL | hsl(235, 31%, 31%) |
| OKLCH | oklch(37.1% 0.077 278.1) |
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 #373B68 | 10.56:1 | AAA | Lc -98.4 | Preferred for body text |
| Black text on #373B68 | 1.98:1 | Fails | Lc 9.5 | Not readable |
| #373B68 text on white | 10.56:1 | AAA | Lc 94.4 | Preferred for body text |
| #373B68 text on black | 1.98:1 | Fails | Lc -8.2 | 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
#F4F5FB
oklch(97.1% 0.008 278.6)
-
Step 100
100
#E7E9F5
oklch(93.6% 0.016 278.5)
-
Step 200
200
#D4D8EF
oklch(88.6% 0.032 277.9)
-
Step 300
300
#B7BEE6
oklch(80.9% 0.057 277.3)
-
Step 400
400
#939BDA
oklch(70.7% 0.092 278.2)
-
Step 500
500
#7981D0
oklch(63.1% 0.119 278)
-
Step 600
600
#6369BD
oklch(55.6% 0.129 278.2)
-
Step 700
700
#5257A3
oklch(49% 0.12 278.1)
-
Step 800
800
#434884
oklch(42.7% 0.099 277.8)
-
Step 900
900 (this color)
#373B68
oklch(37.1% 0.077 278.1)
-
Step 950
950
#21243E
oklch(27.1% 0.048 277.6)
#373B68 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) | #2A416A | 0.023 |
| Deuteranopia (no green cones) | #273D67 | 0.023 |
| Tritanopia (no blue cones) | #27444C | 0.067 |
| Achromatopsia (no color) | #3F3F3F | 0.077 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373B68
#373B68
oklch(37.1% 0.077 278.1)
- #4B4000
#4B4000
oklch(37.2% 0.077 98.2)
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 #373B68, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.048
- Prussian Blue #1D3557 ΔE 0.052
- Twilight Blue #0A437A ΔE 0.052
- Marine Blue #01386A ΔE 0.056
- Dark Blue Grey #1F3B4D ΔE 0.060
- Charcoal #264653 ΔE 0.061
- Dark Slate Blue #483D8B ΔE 0.066
- Onyx #343A40 ΔE 0.071
Use #373B68 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.