#183A80
Closest named color: Twilight Blue (#0A437A). oklch(36.8% 0.125 262.5), rgb(24, 58, 128).
Aa
White text reads best on this color (10.73:1).
About this color
#183A80 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.125 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.029 away. White text reads best on it, at 10.73:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.125) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.95:1 |
| White text | 10.73:1 |
Values
| HEX | #183A80 |
| RGB | rgb(24, 58, 128) |
| HSL | hsl(220, 68%, 30%) |
| OKLCH | oklch(36.8% 0.125 262.5) |
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 #183A80 | 10.73:1 | AAA | Lc -98.4 | Preferred for body text |
| Black text on #183A80 | 1.95:1 | Fails | Lc 9.5 | Not readable |
| #183A80 text on white | 10.73:1 | AAA | Lc 94.4 | Preferred for body text |
| #183A80 text on black | 1.95:1 | Fails | Lc -8.1 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E0EAFD
oklch(93.5% 0.028 263.4)
-
Step 200
200
#C7DAFD
oklch(88.5% 0.053 262.7)
-
Step 300
300
#A0C1FE
oklch(80.9% 0.094 262.4)
-
Step 400
400
#6D9EFE
oklch(70.7% 0.151 262.7)
-
Step 500
500
#4682FB
oklch(63% 0.191 262.5)
-
Step 600
600
#2968EB
oklch(55.7% 0.209 262.5)
-
Step 700
700
#1C55CC
oklch(49.1% 0.194 262.5)
-
Step 800
800
#1947A5
oklch(42.8% 0.16 262.3)
-
Step 900
900 (this color)
#183A80
oklch(36.8% 0.125 262.5)
-
Step 950
950
#10244D
oklch(27% 0.08 262.7)
#183A80 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) | #064382 | 0.025 |
| Deuteranopia (no green cones) | #00397F | 0.015 |
| Tritanopia (no blue cones) | #004B57 | 0.097 |
| Achromatopsia (no color) | #3E3E3E | 0.125 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183A80
#183A80
oklch(36.8% 0.125 262.5)
- #533B00
#533B00
oklch(36.9% 0.076 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 #183A80, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.029
- Marine Blue #01386A ΔE 0.042
- Cobalt #1E488F ΔE 0.046
- Light Navy #155084 ΔE 0.063
- Marine #042E60 ΔE 0.068
- Dark Slate Blue #483D8B ΔE 0.069
- Prussian Blue #1D3557 ΔE 0.071
- Sapphire #2138AB ΔE 0.072
Use #183A80 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.