#373B4E
Closest named color: Onyx (#343A40). oklch(35.7% 0.033 275.3), rgb(55, 59, 78).
Aa
White text reads best on this color (11.06:1).
About this color
#373B4E is a dark, muted blue. In OKLCH its lightness is 36%, its chroma 0.033 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is Onyx (#343A40), ΔE 0.025 away. White text reads best on it, at 11.06:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | muted (0.033) |
| Temperature | cool |
| Nearest name | Onyx (#343A40) |
| Black text | 1.89:1 |
| White text | 11.06:1 |
Values
| HEX | #373B4E |
| RGB | rgb(55, 59, 78) |
| HSL | hsl(230, 17%, 26%) |
| OKLCH | oklch(35.7% 0.033 275.3) |
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 #373B4E | 11.06:1 | AAA | Lc -99.4 | Preferred for body text |
| Black text on #373B4E | 1.89:1 | Fails | Lc 8.3 | Not readable |
| #373B4E text on white | 11.06:1 | AAA | Lc 95.6 | Preferred for body text |
| #373B4E text on black | 1.89:1 | Fails | Lc 0.0 | 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
#F5F5F8
oklch(97.1% 0.004 286.3)
-
Step 100
100
#E8E9EF
oklch(93.5% 0.008 278.6)
-
Step 200
200
#D6D9E3
oklch(88.6% 0.014 272.7)
-
Step 300
300
#BCC0D1
oklch(81% 0.024 275.3)
-
Step 400
400
#999FBA
oklch(70.7% 0.04 275.5)
-
Step 500
500
#8087A9
oklch(63% 0.052 275.7)
-
Step 600
600
#6A7194
oklch(55.6% 0.055 275.7)
-
Step 700
700
#585F7E
oklch(49.2% 0.05 274.5)
-
Step 800
800
#484D67
oklch(42.6% 0.044 275.9)
-
Step 900
900 (this color)
#373B4E
oklch(35.7% 0.033 275.3)
-
Step 950
950
#232631
oklch(27% 0.021 273)
#373B4E 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) | #363D4F | 0.006 |
| Deuteranopia (no green cones) | #343B4E | 0.005 |
| Tritanopia (no blue cones) | #313F41 | 0.032 |
| Achromatopsia (no color) | #3C3C3C | 0.033 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373B4E
#373B4E
oklch(35.7% 0.033 275.3)
- #423C28
#423C28
oklch(35.6% 0.033 93.4)
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 #373B4E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Onyx #343A40 ΔE 0.025
- Dark Blue Grey #1F3B4D ΔE 0.033
- Charcoal Grey #3C4142 ΔE 0.034
- Dark Grey Blue #29465B ΔE 0.038
- Charcoal #264653 ΔE 0.038
- Gunmetal #293241 ΔE 0.042
- Prussian Blue #1D3557 ΔE 0.047
- Space Cadet #2B2D42 ΔE 0.052
Use #373B4E 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.