#183571
Closest named color: Marine Blue (#01386A). oklch(34.4% 0.11 262.7), rgb(24, 53, 113).
Aa
White text reads best on this color (11.75:1).
About this color
#183571 is a dark, moderately saturated blue. In OKLCH its lightness is 34%, its chroma 0.110 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.021 away. White text reads best on it, at 11.75:1.
| Hue family | Blues |
| Lightness | dark (34%) |
| Chroma | moderately saturated (0.110) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.78:1 |
| White text | 11.75:1 |
Values
| HEX | #183571 |
| RGB | rgb(24, 53, 113) |
| HSL | hsl(220, 65%, 27%) |
| OKLCH | oklch(34.4% 0.11 262.7) |
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 #183571 | 11.75:1 | AAA | Lc -100.3 | Preferred for body text |
| Black text on #183571 | 1.78:1 | Fails | Lc 0.0 | Not readable |
| #183571 text on white | 11.75:1 | AAA | Lc 96.6 | Preferred for body text |
| #183571 text on black | 1.78:1 | 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E1EAFA
oklch(93.5% 0.024 262.1)
-
Step 200
200
#C9DAF8
oklch(88.5% 0.045 261.9)
-
Step 300
300
#A4C1F7
oklch(80.9% 0.083 262.6)
-
Step 400
400
#749FF2
oklch(70.7% 0.131 262.7)
-
Step 500
500
#5084EE
oklch(63% 0.169 262.8)
-
Step 600
600
#356BDC
oklch(55.5% 0.183 262.7)
-
Step 700
700
#2859BF
oklch(49.2% 0.169 262.6)
-
Step 800
800
#22499B
oklch(42.7% 0.141 262.8)
-
Step 900
900 (this color)
#183571
oklch(34.4% 0.11 262.7)
-
Step 950
950
#132548
oklch(27% 0.069 262.3)
#183571 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) | #103C73 | 0.020 |
| Deuteranopia (no green cones) | #003470 | 0.017 |
| Tritanopia (no blue cones) | #00434D | 0.086 |
| Achromatopsia (no color) | #383838 | 0.110 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183571
#183571
oklch(34.4% 0.11 262.7)
- #4B3500
#4B3500
oklch(34.5% 0.071 82.8)
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 #183571, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.021
- Marine #042E60 ΔE 0.041
- Twilight Blue #0A437A ΔE 0.041
- Prussian Blue #1D3557 ΔE 0.046
- Midnight Blue #191970 ΔE 0.069
- Dark Blue Grey #1F3B4D ΔE 0.070
- Cobalt #1E488F ΔE 0.072
- Midnight Green #073B4C ΔE 0.074
Use #183571 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.