#374B57
Closest named color: Dark Slate Gray (#2F4F4F). oklch(40.1% 0.032 235), rgb(55, 75, 87).
Aa
White text reads best on this color (9.10:1).
About this color
#374B57 is a dark, muted blue. In OKLCH its lightness is 40%, its chroma 0.032 and its hue 235°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Gray (#2F4F4F), ΔE 0.024 away. White text reads best on it, at 9.10:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | muted (0.032) |
| Temperature | cool |
| Nearest name | Dark Slate Gray (#2F4F4F) |
| Black text | 2.30:1 |
| White text | 9.10:1 |
Values
| HEX | #374B57 |
| RGB | rgb(55, 75, 87) |
| HSL | hsl(203, 23%, 28%) |
| OKLCH | oklch(40.1% 0.032 235) |
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 #374B57 | 9.10:1 | AAA | Lc -95.3 | Preferred for body text |
| Black text on #374B57 | 2.30:1 | Fails | Lc 13.0 | Not readable |
| #374B57 text on white | 9.10:1 | AAA | Lc 90.9 | Preferred for body text |
| #374B57 text on black | 2.30:1 | Fails | Lc -11.4 | 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
#F3F6F7
oklch(97.1% 0.003 219.5)
-
Step 100
100
#E6EBEE
oklch(93.7% 0.007 233.6)
-
Step 200
200
#D1DBE1
oklch(88.6% 0.014 233.8)
-
Step 300
300
#B2C4CE
oklch(81% 0.024 231.9)
-
Step 400
400
#8AA5B6
oklch(70.7% 0.039 235.7)
-
Step 500
500
#6C8FA3
oklch(63.1% 0.049 233.6)
-
Step 600
600
#54798E
oklch(55.6% 0.053 233.9)
-
Step 700
700
#446679
oklch(49.2% 0.05 233.6)
-
Step 800
800
#385363
oklch(42.7% 0.042 235.1)
-
Step 900
900 (this color)
#374B57
oklch(40.1% 0.032 235)
-
Step 950
950
#1D282F
oklch(27% 0.02 236.4)
#374B57 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) | #454A58 | 0.021 |
| Deuteranopia (no green cones) | #414757 | 0.018 |
| Tritanopia (no blue cones) | #2C4E4F | 0.024 |
| Achromatopsia (no color) | #484848 | 0.032 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #374B57
#374B57
oklch(40.1% 0.032 235)
- #564437
#564437
oklch(40.2% 0.033 57.5)
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 #374B57, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Gray #2F4F4F ΔE 0.024
- Dark Grey Blue #29465B ΔE 0.027
- Charcoal #264653 ΔE 0.029
- Charcoal Grey #3C4142 ΔE 0.040
- Deep Teal #00555A ΔE 0.047
- Dark Teal #014D4E ΔE 0.049
- Dark Blue Green #005249 ΔE 0.057
- Onyx #343A40 ΔE 0.059
Use #374B57 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.