#373C8E
Closest named color: Dark Slate Blue (#483D8B). oklch(40.1% 0.134 275.9), rgb(55, 60, 142).
Aa
White text reads best on this color (9.54:1).
About this color
#373C8E is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.134 and its hue 276°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.028 away. White text reads best on it, at 9.54:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.134) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.19:1 |
| White text | 9.54:1 |
Values
| HEX | #373C8E |
| RGB | rgb(55, 60, 142) |
| HSL | hsl(237, 44%, 39%) |
| OKLCH | oklch(40.1% 0.134 275.9) |
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 #373C8E | 9.54:1 | AAA | Lc -96.1 | Preferred for body text |
| Black text on #373C8E | 2.19:1 | Fails | Lc 12.2 | Not readable |
| #373C8E text on white | 9.54:1 | AAA | Lc 91.8 | Preferred for body text |
| #373C8E text on black | 2.19:1 | Fails | Lc -10.6 | 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
#F3F5FF
oklch(97.2% 0.013 277.1)
-
Step 100
100
#E4E9FE
oklch(93.7% 0.029 275.2)
-
Step 200
200
#CED7FF
oklch(88.5% 0.056 275.2)
-
Step 300
300
#AFBCFF
oklch(80.9% 0.096 275.6)
-
Step 400
400
#8796FF
oklch(70.7% 0.154 275.6)
-
Step 500
500
#6D77FF
oklch(63.2% 0.199 275.9)
-
Step 600
600
#5759F1
oklch(55.6% 0.222 275.8)
-
Step 700
700
#4847D2
oklch(49% 0.207 275.9)
-
Step 800
800
#3B3CAA
oklch(42.8% 0.171 276)
-
Step 900
900 (this color)
#373C8E
oklch(40.1% 0.134 275.9)
-
Step 950
950
#1C204F
oklch(27% 0.085 275.5)
#373C8E 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) | #004991 | 0.050 |
| Deuteranopia (no green cones) | #00428C | 0.047 |
| Tritanopia (no blue cones) | #004F5F | 0.114 |
| Achromatopsia (no color) | #454545 | 0.134 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373C8E
#373C8E
oklch(40.1% 0.134 275.9)
- #554700
#554700
oklch(40% 0.082 96.2)
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 #373C8E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.028
- Blueberry #464196 ΔE 0.031
- Cobalt #1E488F ΔE 0.038
- Sapphire #2138AB ΔE 0.056
- Twilight Blue #0A437A ΔE 0.058
- Dusk Blue #26538D ΔE 0.064
- Light Navy #155084 ΔE 0.065
- Twilight #4E518B ΔE 0.072
Use #373C8E 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.