#373783
Closest named color: Dark Slate Blue (#483D8B). oklch(38.2% 0.125 278.7), rgb(55, 55, 131).
Aa
White text reads best on this color (10.31:1).
About this color
#373783 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.125 and its hue 279°. 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 10.31:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.125) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.03:1 |
| White text | 10.31:1 |
Values
| HEX | #373783 |
| RGB | rgb(55, 55, 131) |
| HSL | hsl(240, 41%, 36%) |
| OKLCH | oklch(38.2% 0.125 278.7) |
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 #373783 | 10.31:1 | AAA | Lc -97.7 | Preferred for body text |
| Black text on #373783 | 2.03:1 | Fails | Lc 10.3 | Not readable |
| #373783 text on white | 10.31:1 | AAA | Lc 93.6 | Preferred for body text |
| #373783 text on black | 2.03:1 | Fails | Lc -8.9 | 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
#F3F5FE
oklch(97.1% 0.012 276.1)
-
Step 100
100
#E5E8FC
oklch(93.5% 0.027 279.1)
-
Step 200
200
#D1D6FC
oklch(88.4% 0.053 279.4)
-
Step 300
300
#B3BBFD
oklch(81% 0.094 278.7)
-
Step 400
400
#8D95FC
oklch(70.8% 0.149 278.5)
-
Step 500
500
#7476F9
oklch(63.1% 0.191 278.8)
-
Step 600
600
#5F5AE8
oklch(55.5% 0.208 278.8)
-
Step 700
700
#4F49CA
oklch(49.1% 0.193 278.6)
-
Step 800
800
#403DA3
oklch(42.7% 0.16 278.5)
-
Step 900
900 (this color)
#373783
oklch(38.2% 0.125 278.7)
-
Step 950
950
#1F204C
oklch(27% 0.08 278.7)
#373783 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) | #004386 | 0.053 |
| Deuteranopia (no green cones) | #003D81 | 0.051 |
| Tritanopia (no blue cones) | #0E4957 | 0.109 |
| Achromatopsia (no color) | #404040 | 0.125 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373783
#373783
oklch(38.2% 0.125 278.7)
- #4E4300
#4E4300
oklch(38.3% 0.079 98.6)
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 #373783, 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
- Blueberry #464196 ΔE 0.048
- Cobalt #1E488F ΔE 0.051
- Twilight Blue #0A437A ΔE 0.055
- Marine Blue #01386A ΔE 0.071
- Sapphire #2138AB ΔE 0.071
- Light Navy #155084 ΔE 0.073
- Dusk Blue #26538D ΔE 0.077
Use #373783 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.