#183C80
Closest named color: Twilight Blue (#0A437A). oklch(37.3% 0.122 261.6), rgb(24, 60, 128).
Aa
White text reads best on this color (10.51:1).
About this color
#183C80 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.122 and its hue 262°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.024 away. White text reads best on it, at 10.51:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.122) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.99:1 |
| White text | 10.51:1 |
Values
| HEX | #183C80 |
| RGB | rgb(24, 60, 128) |
| HSL | hsl(219, 68%, 30%) |
| OKLCH | oklch(37.3% 0.122 261.6) |
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 #183C80 | 10.51:1 | AAA | Lc -98.0 | Preferred for body text |
| Black text on #183C80 | 1.99:1 | Fails | Lc 10.0 | Not readable |
| #183C80 text on white | 10.51:1 | AAA | Lc 94.0 | Preferred for body text |
| #183C80 text on black | 1.99:1 | Fails | Lc -8.6 | 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
#E0EAFC
oklch(93.5% 0.027 262.3)
-
Step 200
200
#C7DAFC
oklch(88.5% 0.051 262.1)
-
Step 300
300
#A0C1FD
oklch(80.9% 0.093 262.1)
-
Step 400
400
#6C9FFB
oklch(70.7% 0.146 261.4)
-
Step 500
500
#4483F9
oklch(63% 0.188 261.6)
-
Step 600
600
#2669E8
oklch(55.6% 0.204 261.6)
-
Step 700
700
#1957CA
oklch(49.2% 0.19 261.5)
-
Step 800
800
#1748A3
oklch(42.8% 0.157 261.4)
-
Step 900
900 (this color)
#183C80
oklch(37.3% 0.122 261.6)
-
Step 950
950
#10244C
oklch(26.9% 0.079 262.4)
#183C80 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) | #0F4482 | 0.022 |
| Deuteranopia (no green cones) | #003B7F | 0.015 |
| Tritanopia (no blue cones) | #004C58 | 0.094 |
| Achromatopsia (no color) | #3F3F3F | 0.123 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183C80
#183C80
oklch(37.3% 0.122 261.6)
- #553B00
#553B00
oklch(37.2% 0.077 80.7)
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 #183C80, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.024
- Cobalt #1E488F ΔE 0.042
- Marine Blue #01386A ΔE 0.043
- Light Navy #155084 ΔE 0.058
- Dark Slate Blue #483D8B ΔE 0.067
- Deep Sea Blue #015482 ΔE 0.069
- Marine #042E60 ΔE 0.071
- Dusk Blue #26538D ΔE 0.071
Use #183C80 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.