#373F7D
Closest named color: Dark Slate Blue (#483D8B). oklch(39.4% 0.104 275.1), rgb(55, 63, 125).
Aa
White text reads best on this color (9.67:1).
About this color
#373F7D is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.104 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.036 away. White text reads best on it, at 9.67:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.104) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.16:1 |
| White text | 9.67:1 |
Values
| HEX | #373F7D |
| RGB | rgb(55, 63, 125) |
| HSL | hsl(233, 39%, 35%) |
| OKLCH | oklch(39.4% 0.104 275.1) |
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 #373F7D | 9.67:1 | AAA | Lc -96.5 | Preferred for body text |
| Black text on #373F7D | 2.16:1 | Fails | Lc 11.7 | Not readable |
| #373F7D text on white | 9.67:1 | AAA | Lc 92.2 | Preferred for body text |
| #373F7D text on black | 2.16:1 | Fails | Lc -10.2 | 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
#E5E9F9
oklch(93.6% 0.022 274.7)
-
Step 200
200
#D0D8F7
oklch(88.6% 0.044 274)
-
Step 300
300
#B1BDF4
oklch(80.8% 0.079 274.9)
-
Step 400
400
#8A99EE
oklch(70.6% 0.125 275.1)
-
Step 500
500
#6F7EE8
oklch(63.2% 0.159 274.9)
-
Step 600
600
#5964D6
oklch(55.5% 0.173 275.1)
-
Step 700
700
#4952BA
oklch(49% 0.162 275)
-
Step 800
800
#3C4496
oklch(42.7% 0.133 275.1)
-
Step 900
900 (this color)
#373F7D
oklch(39.4% 0.104 275.1)
-
Step 950
950
#1E2346
oklch(27.1% 0.065 275.1)
#373F7D 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) | #22477F | 0.031 |
| Deuteranopia (no green cones) | #1A427C | 0.033 |
| Tritanopia (no blue cones) | #154D58 | 0.092 |
| Achromatopsia (no color) | #444444 | 0.104 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373F7D
#373F7D
oklch(39.4% 0.104 275.1)
- #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 #373F7D, 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
- Cobalt #1E488F ΔE 0.042
- Twilight Blue #0A437A ΔE 0.043
- Blueberry #464196 ΔE 0.048
- Light Navy #155084 ΔE 0.054
- Dusk Blue #26538D ΔE 0.059
- Deep Sea Blue #015482 ΔE 0.067
- Twilight #4E518B ΔE 0.067
Use #373F7D 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.