#183D80
Closest named color: Twilight Blue (#0A437A). oklch(37.5% 0.121 261.1), rgb(24, 61, 128).
Aa
White text reads best on this color (10.40:1).
About this color
#183D80 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.121 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.022 away. White text reads best on it, at 10.40:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.121) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.01:1 |
| White text | 10.40:1 |
Values
| HEX | #183D80 |
| RGB | rgb(24, 61, 128) |
| HSL | hsl(219, 68%, 30%) |
| OKLCH | oklch(37.5% 0.121 261.1) |
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 #183D80 | 10.40:1 | AAA | Lc -97.8 | Preferred for body text |
| Black text on #183D80 | 2.01:1 | Fails | Lc 10.2 | Not readable |
| #183D80 text on white | 10.40:1 | AAA | Lc 93.7 | Preferred for body text |
| #183D80 text on black | 2.01:1 | Fails | Lc -8.8 | 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
#C7DAFB
oklch(88.5% 0.05 261.5)
-
Step 300
300
#A0C2FC
oklch(81% 0.09 260.9)
-
Step 400
400
#6B9FFA
oklch(70.6% 0.145 260.9)
-
Step 500
500
#4484F8
oklch(63.2% 0.186 261.1)
-
Step 600
600
#246AE7
oklch(55.6% 0.202 261)
-
Step 700
700
#1757C9
oklch(49.1% 0.189 261.1)
-
Step 800
800
#1648A2
oklch(42.7% 0.155 261.1)
-
Step 900
900 (this color)
#183D80
oklch(37.5% 0.121 261.1)
-
Step 950
950
#0F254B
oklch(27% 0.076 260.5)
#183D80 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) | #134582 | 0.022 |
| Deuteranopia (no green cones) | #003B7F | 0.016 |
| Tritanopia (no blue cones) | #004D58 | 0.094 |
| Achromatopsia (no color) | #404040 | 0.121 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183D80
#183D80
oklch(37.5% 0.121 261.1)
- #563C00
#563C00
oklch(37.6% 0.078 81.1)
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 #183D80, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.022
- Cobalt #1E488F ΔE 0.039
- Marine Blue #01386A ΔE 0.044
- Light Navy #155084 ΔE 0.055
- Dark Slate Blue #483D8B ΔE 0.066
- Deep Sea Blue #015482 ΔE 0.067
- Dusk Blue #26538D ΔE 0.068
- Prussian Blue #1D3557 ΔE 0.072
Use #183D80 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.