#373B7E
Closest named color: Dark Slate Blue (#483D8B). oklch(38.7% 0.111 277.3), rgb(55, 59, 126).
Aa
White text reads best on this color (10.05:1).
About this color
#373B7E is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.111 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.036 away. White text reads best on it, at 10.05:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.111) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.08:1 |
| White text | 10.05:1 |
Values
| HEX | #373B7E |
| RGB | rgb(55, 59, 126) |
| HSL | hsl(237, 39%, 35%) |
| OKLCH | oklch(38.7% 0.111 277.3) |
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 #373B7E | 10.05:1 | AAA | Lc -97.2 | Preferred for body text |
| Black text on #373B7E | 2.08:1 | Fails | Lc 10.8 | Not readable |
| #373B7E text on white | 10.05:1 | AAA | Lc 93.1 | Preferred for body text |
| #373B7E text on black | 2.08:1 | Fails | Lc -9.4 | 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
#E5E9FA
oklch(93.6% 0.023 275.4)
-
Step 200
200
#D1D7F8
oklch(88.5% 0.046 277.3)
-
Step 300
300
#B3BCF7
oklch(80.9% 0.084 277.6)
-
Step 400
400
#8C97F3
oklch(70.6% 0.135 277.2)
-
Step 500
500
#727BEE
oklch(63.2% 0.17 277)
-
Step 600
600
#5D60DD
oklch(55.6% 0.187 277.4)
-
Step 700
700
#4D4FBF
oklch(49.1% 0.172 277.2)
-
Step 800
800
#3F419B
oklch(42.7% 0.143 277.5)
-
Step 900
900 (this color)
#373B7E
oklch(38.7% 0.111 277.3)
-
Step 950
950
#1F2248
oklch(27.1% 0.07 277.3)
#373B7E 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) | #184580 | 0.040 |
| Deuteranopia (no green cones) | #0D3F7D | 0.043 |
| Tritanopia (no blue cones) | #154A56 | 0.098 |
| Achromatopsia (no color) | #424242 | 0.112 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373B7E
#373B7E
oklch(38.7% 0.111 277.3)
- #504400
#504400
oklch(38.7% 0.08 97.7)
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 #373B7E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.036
- Twilight Blue #0A437A ΔE 0.047
- Cobalt #1E488F ΔE 0.047
- Blueberry #464196 ΔE 0.049
- Light Navy #155084 ΔE 0.063
- Marine Blue #01386A ΔE 0.066
- Dusk Blue #26538D ΔE 0.068
- Twilight #4E518B ΔE 0.076
Use #373B7E 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.