#373E8B
Closest named color: Dark Slate Blue (#483D8B). oklch(40.3% 0.126 275.3), rgb(55, 62, 139).
Aa
White text reads best on this color (9.44:1).
About this color
#373E8B is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.126 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.026 away. White text reads best on it, at 9.44:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.126) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.22:1 |
| White text | 9.44:1 |
Values
| HEX | #373E8B |
| RGB | rgb(55, 62, 139) |
| HSL | hsl(235, 43%, 38%) |
| OKLCH | oklch(40.3% 0.126 275.3) |
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 #373E8B | 9.44:1 | AAA | Lc -95.9 | Preferred for body text |
| Black text on #373E8B | 2.22:1 | Fails | Lc 12.4 | Not readable |
| #373E8B text on white | 9.44:1 | AAA | Lc 91.5 | Preferred for body text |
| #373E8B text on black | 2.22:1 | Fails | Lc -10.8 | 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 800.
-
Step 50
50
#F3F5FC
oklch(97.1% 0.01 273.4)
-
Step 100
100
#E5E9F9
oklch(93.6% 0.022 274.7)
-
Step 200
200
#D1D8F5
oklch(88.6% 0.041 274.8)
-
Step 300
300
#B2BDF1
oklch(80.8% 0.075 275.3)
-
Step 400
400
#8C9AEA
oklch(70.8% 0.118 275.4)
-
Step 500
500
#717FE3
oklch(63.2% 0.15 275.3)
-
Step 600
600
#5A66D1
oklch(55.6% 0.163 275)
-
Step 700
700
#4B54B5
oklch(49.2% 0.152 275.3)
-
Step 800
800 (this color)
#373E8B
oklch(40.3% 0.126 275.3)
-
Step 900
900
#343B75
oklch(37.8% 0.098 275.5)
-
Step 950
950
#1E2344
oklch(27% 0.061 275)
#373E8B 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) | #0C4A8E | 0.046 |
| Deuteranopia (no green cones) | #004389 | 0.046 |
| Tritanopia (no blue cones) | #00505E | 0.111 |
| Achromatopsia (no color) | #464646 | 0.127 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373E8B
#373E8B
oklch(40.3% 0.126 275.3)
- #564700
#564700
oklch(40.2% 0.082 95.2)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes and gradients that use #373E8B
These curated palettes and gradients contain exactly #373E8B. Open one to see the full color scheme around it.
Palettes
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.026
- Blueberry #464196 ΔE 0.031
- Cobalt #1E488F ΔE 0.035
- Twilight Blue #0A437A ΔE 0.054
- Dusk Blue #26538D ΔE 0.058
- Light Navy #155084 ΔE 0.059
- Sapphire #2138AB ΔE 0.061
- Twilight #4E518B ΔE 0.067
Use #373E8B 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.