#373F53
Closest named color: Dark Grey Blue (#29465B). oklch(36.9% 0.036 267.7), rgb(55, 63, 83).
Aa
White text reads best on this color (10.50:1).
About this color
#373F53 is a dark, muted blue. In OKLCH its lightness is 37%, its chroma 0.036 and its hue 268°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.027 away. White text reads best on it, at 10.50:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | muted (0.036) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 1.99:1 |
| White text | 10.50:1 |
Values
| HEX | #373F53 |
| RGB | rgb(55, 63, 83) |
| HSL | hsl(223, 20%, 27%) |
| OKLCH | oklch(36.9% 0.036 267.7) |
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 #373F53 | 10.50:1 | AAA | Lc -98.4 | Preferred for body text |
| Black text on #373F53 | 1.99:1 | Fails | Lc 9.5 | Not readable |
| #373F53 text on white | 10.50:1 | AAA | Lc 94.4 | Preferred for body text |
| #373F53 text on black | 1.99:1 | Fails | Lc -8.2 | 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
#F4F5F8
oklch(97% 0.004 271.4)
-
Step 100
100
#E7EAEF
oklch(93.6% 0.007 260.7)
-
Step 200
200
#D5D9E3
oklch(88.5% 0.014 268.5)
-
Step 300
300
#B9C0D3
oklch(80.8% 0.028 269.6)
-
Step 400
400
#95A0BD
oklch(70.7% 0.044 268.9)
-
Step 500
500
#7B89AC
oklch(63.2% 0.055 267.8)
-
Step 600
600
#647297
oklch(55.5% 0.06 268.4)
-
Step 700
700
#536081
oklch(49.2% 0.056 267.7)
-
Step 800
800
#444E69
oklch(42.6% 0.047 268.6)
-
Step 900
900 (this color)
#373F53
oklch(36.9% 0.036 267.7)
-
Step 950
950
#212632
oklch(26.9% 0.024 267.1)
#373F53 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) | #394054 | 0.005 |
| Deuteranopia (no green cones) | #363E53 | 0.004 |
| Tritanopia (no blue cones) | #2F4346 | 0.032 |
| Achromatopsia (no color) | #3F3F3F | 0.036 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373F53
#373F53
oklch(36.9% 0.036 267.7)
- #483E29
#483E29
oklch(36.8% 0.036 85.2)
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 #373F53, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.027
- Charcoal #264653 ΔE 0.030
- Charcoal Grey #3C4142 ΔE 0.033
- Onyx #343A40 ΔE 0.034
- Dark Blue Grey #1F3B4D ΔE 0.038
- Prussian Blue #1D3557 ΔE 0.053
- Gunmetal #293241 ΔE 0.054
- Dark Slate Gray #2F4F4F ΔE 0.055
Use #373F53 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.