#183B61
Closest named color: Prussian Blue (#1D3557). oklch(34.7% 0.078 252.6), rgb(24, 59, 97).
Aa
White text reads best on this color (11.43:1).
About this color
#183B61 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.078 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.023 away. White text reads best on it, at 11.43:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.078) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.83:1 |
| White text | 11.43:1 |
Values
| HEX | #183B61 |
| RGB | rgb(24, 59, 97) |
| HSL | hsl(211, 60%, 24%) |
| OKLCH | oklch(34.7% 0.078 252.6) |
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 #183B61 | 11.43:1 | AAA | Lc -99.8 | Preferred for body text |
| Black text on #183B61 | 1.83:1 | Fails | Lc 7.8 | Not readable |
| #183B61 text on white | 11.43:1 | AAA | Lc 96.1 | Preferred for body text |
| #183B61 text on black | 1.83:1 | Fails | Lc 0.0 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E2EBF5
oklch(93.6% 0.017 250.8)
-
Step 200
200
#CADBEF
oklch(88.5% 0.033 252.5)
-
Step 300
300
#A6C4E6
oklch(81% 0.058 251.8)
-
Step 400
400
#76A4DA
oklch(70.7% 0.094 253)
-
Step 500
500
#518DD0
oklch(63.2% 0.119 252.5)
-
Step 600
600
#3375BD
oklch(55.5% 0.131 252.9)
-
Step 700
700
#2562A3
oklch(49.1% 0.121 252.8)
-
Step 800
800
#205084
oklch(42.6% 0.101 252.8)
-
Step 900
900 (this color)
#183B61
oklch(34.7% 0.078 252.6)
-
Step 950
950
#14273E
oklch(26.9% 0.05 254.1)
#183B61 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) | #2A3D63 | 0.022 |
| Deuteranopia (no green cones) | #1F3760 | 0.013 |
| Tritanopia (no blue cones) | #004449 | 0.060 |
| Achromatopsia (no color) | #3A3A3A | 0.078 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #183B61
#183B61
oklch(34.7% 0.078 252.6)
- #513200
#513200
oklch(34.6% 0.074 71.8)
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 #183B61, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.023
- Marine Blue #01386A ΔE 0.025
- Dark Blue Grey #1F3B4D ΔE 0.036
- Midnight Green #073B4C ΔE 0.041
- Dark Grey Blue #29465B ΔE 0.045
- Twilight Blue #0A437A ΔE 0.045
- Marine #042E60 ΔE 0.046
- Charcoal #264653 ΔE 0.052
Use #183B61 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.