#374C59
Closest named color: Dark Slate Gray (#2F4F4F). oklch(40.4% 0.034 235.9), rgb(55, 76, 89).
Aa
White text reads best on this color (8.97:1).
About this color
#374C59 is a dark, muted blue. In OKLCH its lightness is 40%, its chroma 0.034 and its hue 236°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Gray (#2F4F4F), ΔE 0.025 away. White text reads best on it, at 8.97:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | muted (0.034) |
| Temperature | cool |
| Nearest name | Dark Slate Gray (#2F4F4F) |
| Black text | 2.34:1 |
| White text | 8.97:1 |
Values
| HEX | #374C59 |
| RGB | rgb(55, 76, 89) |
| HSL | hsl(203, 24%, 28%) |
| OKLCH | oklch(40.4% 0.034 235.9) |
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 #374C59 | 8.97:1 | AAA | Lc -95.0 | Preferred for body text |
| Black text on #374C59 | 2.34:1 | Fails | Lc 13.4 | Not readable |
| #374C59 text on white | 8.97:1 | AAA | Lc 90.6 | Preferred for body text |
| #374C59 text on black | 2.34:1 | Fails | Lc -11.7 | 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 800.
-
Step 50
50
#F4F6F7
oklch(97.2% 0.003 228.8)
-
Step 100
100
#E6EAED
oklch(93.5% 0.006 239.8)
-
Step 200
200
#D3DADF
oklch(88.4% 0.01 238.5)
-
Step 300
300
#B5C3CC
oklch(80.9% 0.02 235.8)
-
Step 400
400
#8EA4B2
oklch(70.6% 0.032 235.9)
-
Step 500
500
#728E9F
oklch(63.1% 0.041 234.9)
-
Step 600
600
#5A788A
oklch(55.6% 0.044 235)
-
Step 700
700
#4A6575
oklch(49.2% 0.041 234.7)
-
Step 800
800 (this color)
#374C59
oklch(40.4% 0.034 235.9)
-
Step 900
900
#34444E
oklch(37.7% 0.027 235.9)
-
Step 950
950
#1F282E
oklch(27.1% 0.017 237.4)
#374C59 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) | #464B5A | 0.022 |
| Deuteranopia (no green cones) | #414859 | 0.018 |
| Tritanopia (no blue cones) | #2B4F50 | 0.026 |
| Achromatopsia (no color) | #494949 | 0.034 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #374C59
#374C59
oklch(40.4% 0.034 235.9)
- #584437
#584437
oklch(40.4% 0.035 54.5)
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 #374C59, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Gray #2F4F4F ΔE 0.025
- Dark Grey Blue #29465B ΔE 0.029
- Charcoal #264653 ΔE 0.031
- Charcoal Grey #3C4142 ΔE 0.044
- Deep Teal #00555A ΔE 0.046
- Dark Teal #014D4E ΔE 0.050
- Dark Blue Green #005249 ΔE 0.058
- YInMn Blue #415A77 ΔE 0.061
Use #374C59 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.