#183E7D
Closest named color: Twilight Blue (#0A437A). oklch(37.5% 0.116 260), rgb(24, 62, 125).
Aa
White text reads best on this color (10.37:1).
About this color
#183E7D is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.116 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.017 away. White text reads best on it, at 10.37:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.116) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.02:1 |
| White text | 10.37:1 |
Values
| HEX | #183E7D |
| RGB | rgb(24, 62, 125) |
| HSL | hsl(217, 68%, 29%) |
| OKLCH | oklch(37.5% 0.116 260) |
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 #183E7D | 10.37:1 | AAA | Lc -97.7 | Preferred for body text |
| Black text on #183E7D | 2.02:1 | Fails | Lc 10.2 | Not readable |
| #183E7D text on white | 10.37:1 | AAA | Lc 93.7 | Preferred for body text |
| #183E7D text on black | 2.02:1 | 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E0EBFB
oklch(93.7% 0.025 257.6)
-
Step 200
200
#C7DAFA
oklch(88.4% 0.049 260.9)
-
Step 300
300
#A0C2F9
oklch(80.9% 0.087 259.9)
-
Step 400
400
#6CA0F6
oklch(70.7% 0.138 260)
-
Step 500
500
#4485F3
oklch(63% 0.178 260.2)
-
Step 600
600
#246CE1
oklch(55.6% 0.192 260)
-
Step 700
700
#1659C4
oklch(49.1% 0.18 260.1)
-
Step 800
800
#164A9E
oklch(42.8% 0.147 259.9)
-
Step 900
900 (this color)
#183E7D
oklch(37.5% 0.116 260)
-
Step 950
950
#0F254A
oklch(27% 0.074 260.2)
#183E7D 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) | #1A457F | 0.021 |
| Deuteranopia (no green cones) | #003C7C | 0.016 |
| Tritanopia (no blue cones) | #004D57 | 0.090 |
| Achromatopsia (no color) | #404040 | 0.116 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183E7D
#183E7D
oklch(37.5% 0.116 260)
- #563B00
#563B00
oklch(37.3% 0.077 79.7)
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 #183E7D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.017
- Cobalt #1E488F ΔE 0.041
- Marine Blue #01386A ΔE 0.041
- Light Navy #155084 ΔE 0.053
- Deep Sea Blue #015482 ΔE 0.064
- Prussian Blue #1D3557 ΔE 0.067
- Dusk Blue #26538D ΔE 0.067
- Dark Slate Blue #483D8B ΔE 0.068
Use #183E7D 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.