#183B57
Closest named color: Dark Blue Grey (#1F3B4D). oklch(34.1% 0.064 245.4), rgb(24, 59, 87).
Aa
White text reads best on this color (11.65:1).
About this color
#183B57 is a dark, muted blue. In OKLCH its lightness is 34%, its chroma 0.064 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Blue Grey (#1F3B4D), ΔE 0.019 away. White text reads best on it, at 11.65:1.
| Hue family | Blues |
| Lightness | dark (34%) |
| Chroma | muted (0.064) |
| Temperature | cool |
| Nearest name | Dark Blue Grey (#1F3B4D) |
| Black text | 1.80:1 |
| White text | 11.65:1 |
Values
| HEX | #183B57 |
| RGB | rgb(24, 59, 87) |
| HSL | hsl(207, 57%, 22%) |
| OKLCH | oklch(34.1% 0.064 245.4) |
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 #183B57 | 11.65:1 | AAA | Lc -100.3 | Preferred for body text |
| Black text on #183B57 | 1.80:1 | Fails | Lc 0.0 | Not readable |
| #183B57 text on white | 11.65:1 | AAA | Lc 96.6 | Preferred for body text |
| #183B57 text on black | 1.80:1 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E3EBF3
oklch(93.6% 0.014 248)
-
Step 200
200
#CBDBEA
oklch(88.4% 0.027 246.4)
-
Step 300
300
#A8C4DE
oklch(80.8% 0.048 246.4)
-
Step 400
400
#78A6CE
oklch(70.7% 0.077 245.4)
-
Step 500
500
#548FC1
oklch(63.1% 0.098 245.8)
-
Step 600
600
#3679AD
oklch(55.7% 0.106 244.9)
-
Step 700
700
#286595
oklch(49% 0.099 245.7)
-
Step 800
800
#235379
oklch(42.8% 0.082 245.4)
-
Step 900
900 (this color)
#183B57
oklch(34.1% 0.064 245.4)
-
Step 950
950
#152839
oklch(26.9% 0.04 246.9)
#183B57 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) | #2F3C58 | 0.028 |
| Deuteranopia (no green cones) | #263656 | 0.020 |
| Tritanopia (no blue cones) | #004245 | 0.048 |
| Achromatopsia (no color) | #383838 | 0.064 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183B57
#183B57
oklch(34.1% 0.064 245.4)
- #4E310F
#4E310F
oklch(34.1% 0.063 66.7)
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 #183B57, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Blue Grey #1F3B4D ΔE 0.019
- Prussian Blue #1D3557 ΔE 0.019
- Midnight Green #073B4C ΔE 0.024
- Marine Blue #01386A ΔE 0.039
- Dark Grey Blue #29465B ΔE 0.042
- Charcoal #264653 ΔE 0.043
- Gunmetal #293241 ΔE 0.044
- Onyx #343A40 ΔE 0.051
Use #183B57 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.