#373A7C
Closest named color: Dark Slate Blue (#483D8B). oklch(38.3% 0.11 277.9), rgb(55, 58, 124).
Aa
White text reads best on this color (10.20:1).
About this color
#373A7C is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.110 and its hue 278°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.039 away. White text reads best on it, at 10.20:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.110) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.05:1 |
| White text | 10.20:1 |
Values
| HEX | #373A7C |
| RGB | rgb(55, 58, 124) |
| HSL | hsl(237, 39%, 35%) |
| OKLCH | oklch(38.3% 0.11 277.9) |
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 #373A7C | 10.20:1 | AAA | Lc -97.6 | Preferred for body text |
| Black text on #373A7C | 2.05:1 | Fails | Lc 10.5 | Not readable |
| #373A7C text on white | 10.20:1 | AAA | Lc 93.5 | Preferred for body text |
| #373A7C text on black | 2.05:1 | Fails | Lc -9.0 | 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
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E6E9FA
oklch(93.7% 0.023 277.9)
-
Step 200
200
#D1D7F8
oklch(88.5% 0.046 277.3)
-
Step 300
300
#B4BCF6
oklch(80.9% 0.082 278.3)
-
Step 400
400
#8E97F1
oklch(70.7% 0.131 278.1)
-
Step 500
500
#747BED
oklch(63.2% 0.168 277.8)
-
Step 600
600
#5E60DB
oklch(55.5% 0.184 277.9)
-
Step 700
700
#4E4FBE
oklch(49.1% 0.17 277.7)
-
Step 800
800
#40419A
oklch(42.7% 0.142 278.1)
-
Step 900
900 (this color)
#373A7C
oklch(38.3% 0.11 277.9)
-
Step 950
950
#1F2248
oklch(27.1% 0.07 277.3)
#373A7C 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) | #18447E | 0.041 |
| Deuteranopia (no green cones) | #0E3E7B | 0.043 |
| Tritanopia (no blue cones) | #174955 | 0.096 |
| Achromatopsia (no color) | #414141 | 0.110 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373A7C
#373A7C
oklch(38.3% 0.11 277.9)
- #4F4300
#4F4300
oklch(38.4% 0.079 97.6)
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 #373A7C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.039
- Twilight Blue #0A437A ΔE 0.048
- Cobalt #1E488F ΔE 0.051
- Blueberry #464196 ΔE 0.053
- Marine Blue #01386A ΔE 0.064
- Light Navy #155084 ΔE 0.066
- Dusk Blue #26538D ΔE 0.072
- Dark Grey Blue #29465B ΔE 0.076
Use #373A7C 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.