#373B59
Closest named color: Dark Grey Blue (#29465B). oklch(36.2% 0.052 277.6), rgb(55, 59, 89).
Aa
White text reads best on this color (10.86:1).
About this color
#373B59 is a dark, muted blue. In OKLCH its lightness is 36%, its chroma 0.052 and its hue 278°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.037 away. White text reads best on it, at 10.86:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | muted (0.052) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 1.93:1 |
| White text | 10.86:1 |
Values
| HEX | #373B59 |
| RGB | rgb(55, 59, 89) |
| HSL | hsl(233, 24%, 28%) |
| OKLCH | oklch(36.2% 0.052 277.6) |
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 #373B59 | 10.86:1 | AAA | Lc -99.0 | Preferred for body text |
| Black text on #373B59 | 1.93:1 | Fails | Lc 8.8 | Not readable |
| #373B59 text on white | 10.86:1 | AAA | Lc 95.1 | Preferred for body text |
| #373B59 text on black | 1.93:1 | Fails | Lc -7.5 | 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
#F4F5F9
oklch(97.1% 0.005 275)
-
Step 100
100
#E8E9F2
oklch(93.6% 0.012 281.1)
-
Step 200
200
#D5D8E8
oklch(88.5% 0.022 277.5)
-
Step 300
300
#BABFDA
oklch(80.9% 0.038 277.2)
-
Step 400
400
#979DC8
oklch(70.6% 0.063 278.5)
-
Step 500
500
#7D85BA
oklch(63.1% 0.08 277.2)
-
Step 600
600
#676EA6
oklch(55.6% 0.087 277.7)
-
Step 700
700
#565C8E
oklch(49.2% 0.08 277.8)
-
Step 800
800
#464B73
oklch(42.6% 0.067 277.7)
-
Step 900
900 (this color)
#373B59
oklch(36.2% 0.052 277.6)
-
Step 950
950
#222537
oklch(27% 0.034 276.6)
#373B59 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) | #323E5A | 0.011 |
| Deuteranopia (no green cones) | #2F3C58 | 0.012 |
| Tritanopia (no blue cones) | #2D4146 | 0.046 |
| Achromatopsia (no color) | #3D3D3D | 0.052 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #373B59
#373B59
oklch(36.2% 0.052 277.6)
- #453E1C
#453E1C
oklch(36.3% 0.052 97.9)
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 #373B59, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.037
- Dark Blue Grey #1F3B4D ΔE 0.041
- Prussian Blue #1D3557 ΔE 0.044
- Charcoal #264653 ΔE 0.044
- Onyx #343A40 ΔE 0.044
- Charcoal Grey #3C4142 ΔE 0.050
- Gunmetal #293241 ΔE 0.053
- Midnight Green #073B4C ΔE 0.059
Use #373B59 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.