#183E8B
Closest named color: Cobalt (#1E488F). oklch(38.6% 0.136 262.3), rgb(24, 62, 139).
Aa
White text reads best on this color (9.99:1).
About this color
#183E8B is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.136 and its hue 262°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.030 away. White text reads best on it, at 9.99:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.136) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.10:1 |
| White text | 9.99:1 |
Values
| HEX | #183E8B |
| RGB | rgb(24, 62, 139) |
| HSL | hsl(220, 71%, 32%) |
| OKLCH | oklch(38.6% 0.136 262.3) |
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 #183E8B | 9.99:1 | AAA | Lc -96.9 | Preferred for body text |
| Black text on #183E8B | 2.10:1 | Fails | Lc 11.2 | Not readable |
| #183E8B text on white | 9.99:1 | AAA | Lc 92.7 | Preferred for body text |
| #183E8B text on black | 2.10:1 | Fails | Lc -9.8 | 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
#F1F6FF
oklch(97.2% 0.013 262.4)
-
Step 100
100
#DFEAFE
oklch(93.5% 0.03 262.5)
-
Step 200
200
#C5DAFF
oklch(88.5% 0.056 261.8)
-
Step 300
300
#9FC1FF
oklch(80.9% 0.096 262.2)
-
Step 400
400
#6B9EFF
oklch(70.7% 0.153 262.2)
-
Step 500
500
#4382FF
oklch(63.2% 0.197 262.2)
-
Step 600
600
#1E65F4
oklch(55.6% 0.225 262.2)
-
Step 700
700
#1252D5
oklch(49.1% 0.211 262.4)
-
Step 800
800
#1244AC
oklch(42.6% 0.175 262.4)
-
Step 900
900 (this color)
#183E8B
oklch(38.6% 0.136 262.3)
-
Step 950
950
#0E2450
oklch(27.2% 0.086 262.3)
#183E8B 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) | #00488E | 0.027 |
| Deuteranopia (no green cones) | #003D89 | 0.015 |
| Tritanopia (no blue cones) | #00515E | 0.105 |
| Achromatopsia (no color) | #424242 | 0.136 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183E8B
#183E8B
oklch(38.6% 0.136 262.3)
- #593F00
#593F00
oklch(38.6% 0.08 82.1)
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 #183E8B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.030
- Twilight Blue #0A437A ΔE 0.034
- Light Navy #155084 ΔE 0.054
- Sapphire #2138AB ΔE 0.055
- Marine Blue #01386A ΔE 0.061
- Dark Slate Blue #483D8B ΔE 0.061
- Blueberry #464196 ΔE 0.062
- Dusk Blue #26538D ΔE 0.063
Use #183E8B 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.