#183E80
Closest named color: Twilight Blue (#0A437A). oklch(37.7% 0.12 260.6), rgb(24, 62, 128).
Aa
White text reads best on this color (10.29:1).
About this color
#183E80 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.120 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.020 away. White text reads best on it, at 10.29:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.120) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.03:1 |
| White text | 10.29:1 |
Values
| HEX | #183E80 |
| RGB | rgb(24, 62, 128) |
| HSL | hsl(218, 68%, 30%) |
| OKLCH | oklch(37.7% 0.12 260.6) |
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 #183E80 | 10.29:1 | AAA | Lc -97.6 | Preferred for body text |
| Black text on #183E80 | 2.03:1 | Fails | Lc 10.5 | Not readable |
| #183E80 text on white | 10.29:1 | AAA | Lc 93.5 | Preferred for body text |
| #183E80 text on black | 2.03:1 | Fails | Lc -9.0 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E0EBFC
oklch(93.7% 0.026 259)
-
Step 200
200
#C7DAFB
oklch(88.5% 0.05 261.5)
-
Step 300
300
#9FC2FB
oklch(80.9% 0.09 260)
-
Step 400
400
#6B9FF9
oklch(70.6% 0.144 260.8)
-
Step 500
500
#4384F7
oklch(63.1% 0.185 260.8)
-
Step 600
600
#236BE5
oklch(55.7% 0.199 260.5)
-
Step 700
700
#1558C7
oklch(49.1% 0.185 260.5)
-
Step 800
800
#1549A1
oklch(42.8% 0.153 260.5)
-
Step 900
900 (this color)
#183E80
oklch(37.7% 0.12 260.6)
-
Step 950
950
#0F254B
oklch(27% 0.076 260.5)
#183E80 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) | #164582 | 0.020 |
| Deuteranopia (no green cones) | #003C7F | 0.016 |
| Tritanopia (no blue cones) | #004E59 | 0.093 |
| Achromatopsia (no color) | #404040 | 0.120 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183E80
#183E80
oklch(37.7% 0.12 260.6)
- #573C00
#573C00
oklch(37.7% 0.078 80.1)
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 #183E80, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.020
- Cobalt #1E488F ΔE 0.037
- Marine Blue #01386A ΔE 0.045
- Light Navy #155084 ΔE 0.052
- Deep Sea Blue #015482 ΔE 0.064
- Dark Slate Blue #483D8B ΔE 0.066
- Dusk Blue #26538D ΔE 0.066
- Blueberry #464196 ΔE 0.071
Use #183E80 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.