#373B74
Closest named color: Twilight Blue (#0A437A). oklch(37.9% 0.096 277.8), rgb(55, 59, 116).
Aa
White text reads best on this color (10.29:1).
About this color
#373B74 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.096 and its hue 278°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.046 away. White text reads best on it, at 10.29:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.096) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.04:1 |
| White text | 10.29:1 |
Values
| HEX | #373B74 |
| RGB | rgb(55, 59, 116) |
| HSL | hsl(236, 36%, 34%) |
| OKLCH | oklch(37.9% 0.096 277.8) |
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 #373B74 | 10.29:1 | AAA | Lc -97.8 | Preferred for body text |
| Black text on #373B74 | 2.04:1 | Fails | Lc 10.2 | Not readable |
| #373B74 text on white | 10.29:1 | AAA | Lc 93.7 | Preferred for body text |
| #373B74 text on black | 2.04:1 | Fails | Lc -8.8 | 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
#F4F5FC
oklch(97.1% 0.009 279.7)
-
Step 100
100
#E6E9F8
oklch(93.6% 0.02 276.9)
-
Step 200
200
#D2D7F4
oklch(88.4% 0.04 277.8)
-
Step 300
300
#B5BDEF
oklch(80.9% 0.071 277.6)
-
Step 400
400
#9099E8
oklch(70.7% 0.116 278)
-
Step 500
500
#767EE1
oklch(63.2% 0.147 277.8)
-
Step 600
600
#6065CE
oklch(55.6% 0.159 277.8)
-
Step 700
700
#4F53B3
oklch(49.1% 0.149 277.6)
-
Step 800
800
#414491
oklch(42.7% 0.124 278)
-
Step 900
900 (this color)
#373B74
oklch(37.9% 0.096 277.8)
-
Step 950
950
#202344
oklch(27.2% 0.061 277.6)
#373B74 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) | #224376 | 0.032 |
| Deuteranopia (no green cones) | #1C3E73 | 0.034 |
| Tritanopia (no blue cones) | #1F4752 | 0.083 |
| Achromatopsia (no color) | #404040 | 0.096 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373B74
#373B74
oklch(37.9% 0.096 277.8)
- #4E4200
#4E4200
oklch(38% 0.078 97.4)
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 #373B74, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.046
- Dark Slate Blue #483D8B ΔE 0.048
- Cobalt #1E488F ΔE 0.057
- Marine Blue #01386A ΔE 0.059
- Dark Grey Blue #29465B ΔE 0.063
- Blueberry #464196 ΔE 0.063
- Prussian Blue #1D3557 ΔE 0.065
- Light Navy #155084 ΔE 0.066
Use #373B74 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.