#373F7F
Closest named color: Dark Slate Blue (#483D8B). oklch(39.6% 0.107 275), rgb(55, 63, 127).
Aa
White text reads best on this color (9.63:1).
About this color
#373F7F is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.107 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.034 away. White text reads best on it, at 9.63:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.107) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.17:1 |
| White text | 9.63:1 |
Values
| HEX | #373F7F |
| RGB | rgb(55, 63, 127) |
| HSL | hsl(233, 40%, 36%) |
| OKLCH | oklch(39.6% 0.107 275) |
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 #373F7F | 9.63:1 | AAA | Lc -96.4 | Preferred for body text |
| Black text on #373F7F | 2.17:1 | Fails | Lc 11.8 | Not readable |
| #373F7F text on white | 9.63:1 | AAA | Lc 92.1 | Preferred for body text |
| #373F7F text on black | 2.17:1 | Fails | Lc -10.3 | 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
#D0D7F7
oklch(88.4% 0.045 275.7)
-
Step 300
300
#B1BDF5
oklch(80.9% 0.08 275.1)
-
Step 400
400
#8A99F0
oklch(70.7% 0.128 275.2)
-
Step 500
500
#6F7DEB
oklch(63.1% 0.164 275.2)
-
Step 600
600
#5863D9
oklch(55.5% 0.179 275)
-
Step 700
700
#4951BC
oklch(49% 0.166 275.2)
-
Step 800
800
#3C4398
oklch(42.6% 0.137 275.4)
-
Step 900
900 (this color)
#373F7F
oklch(39.6% 0.107 275)
-
Step 950
950
#1D2247
oklch(26.9% 0.068 275)
#373F7F 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) | #204881 | 0.033 |
| Deuteranopia (no green cones) | #17427E | 0.035 |
| Tritanopia (no blue cones) | #124D59 | 0.094 |
| Achromatopsia (no color) | #454545 | 0.107 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373F7F
#373F7F
oklch(39.6% 0.107 275)
- #544500
#544500
oklch(39.4% 0.081 94.8)
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 #373F7F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.034
- Cobalt #1E488F ΔE 0.040
- Twilight Blue #0A437A ΔE 0.044
- Blueberry #464196 ΔE 0.045
- Light Navy #155084 ΔE 0.054
- Dusk Blue #26538D ΔE 0.058
- Twilight #4E518B ΔE 0.066
- Deep Sea Blue #015482 ΔE 0.067
Use #373F7F 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.