#373B77
Closest named color: Dark Slate Blue (#483D8B). oklch(38.1% 0.101 277.6), rgb(55, 59, 119).
Aa
White text reads best on this color (10.22:1).
About this color
#373B77 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.101 and its hue 278°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.044 away. White text reads best on it, at 10.22:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.101) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.05:1 |
| White text | 10.22:1 |
Values
| HEX | #373B77 |
| RGB | rgb(55, 59, 119) |
| HSL | hsl(236, 37%, 34%) |
| OKLCH | oklch(38.1% 0.101 277.6) |
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 #373B77 | 10.22:1 | AAA | Lc -97.6 | Preferred for body text |
| Black text on #373B77 | 2.05:1 | Fails | Lc 10.4 | Not readable |
| #373B77 text on white | 10.22:1 | AAA | Lc 93.6 | Preferred for body text |
| #373B77 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
#F4F5FC
oklch(97.1% 0.009 279.7)
-
Step 100
100
#E6E9F9
oklch(93.6% 0.022 277.5)
-
Step 200
200
#D2D7F5
oklch(88.5% 0.042 278)
-
Step 300
300
#B4BDF2
oklch(81% 0.076 277.1)
-
Step 400
400
#8F99EB
oklch(70.8% 0.12 277.6)
-
Step 500
500
#757DE5
oklch(63.2% 0.154 277.7)
-
Step 600
600
#5F64D3
oklch(55.7% 0.168 277.5)
-
Step 700
700
#4F52B6
oklch(49.1% 0.155 277.8)
-
Step 800
800
#404494
oklch(42.8% 0.129 277.3)
-
Step 900
900 (this color)
#373B77
oklch(38.1% 0.101 277.6)
-
Step 950
950
#1F2245
oklch(26.9% 0.064 277.4)
#373B77 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) | #1F4479 | 0.035 |
| Deuteranopia (no green cones) | #193E76 | 0.036 |
| Tritanopia (no blue cones) | #1C4853 | 0.088 |
| Achromatopsia (no color) | #414141 | 0.101 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373B77
#373B77
oklch(38.1% 0.101 277.6)
- #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 #373B77, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.044
- Twilight Blue #0A437A ΔE 0.046
- Cobalt #1E488F ΔE 0.054
- Blueberry #464196 ΔE 0.059
- Marine Blue #01386A ΔE 0.061
- Light Navy #155084 ΔE 0.064
- Dark Grey Blue #29465B ΔE 0.067
- Prussian Blue #1D3557 ΔE 0.069
Use #373B77 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.