#181B4A
Closest named color: Dark Indigo (#1F0954). oklch(25.1% 0.086 275.6), rgb(24, 27, 74).
Aa
White text reads best on this color (16.22:1).
About this color
#181B4A is a dark, moderately saturated blue. In OKLCH its lightness is 25%, its chroma 0.086 and its hue 276°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Indigo (#1F0954), ΔE 0.042 away. White text reads best on it, at 16.22:1.
| Hue family | Blues |
| Lightness | dark (25%) |
| Chroma | moderately saturated (0.086) |
| Temperature | cool |
| Nearest name | Dark Indigo (#1F0954) |
| Black text | 1.29:1 |
| White text | 16.22:1 |
Values
| HEX | #181B4A |
| RGB | rgb(24, 27, 74) |
| HSL | hsl(236, 51%, 19%) |
| OKLCH | oklch(25.1% 0.086 275.6) |
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 #181B4A | 16.22:1 | AAA | Lc -105.5 | Preferred for body text |
| Black text on #181B4A | 1.29:1 | Fails | Lc 0.0 | Not readable |
| #181B4A text on white | 16.22:1 | AAA | Lc 103.0 | Preferred for body text |
| #181B4A text on black | 1.29:1 | 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 950.
-
Step 50
50
#F3F5FF
oklch(97.2% 0.013 277.1)
-
Step 100
100
#E4E9FE
oklch(93.7% 0.029 275.2)
-
Step 200
200
#CED7FF
oklch(88.5% 0.056 275.2)
-
Step 300
300
#AFBCFF
oklch(80.9% 0.096 275.6)
-
Step 400
400
#8796FF
oklch(70.7% 0.154 275.6)
-
Step 500
500
#6C77FF
oklch(63.2% 0.199 275.6)
-
Step 600
600
#5658F3
oklch(55.5% 0.226 275.6)
-
Step 700
700
#4747D4
oklch(49.1% 0.21 275.4)
-
Step 800
800
#3A3BAB
oklch(42.6% 0.174 275.7)
-
Step 900
900
#313588
oklch(37.8% 0.136 275.7)
-
Step 950
950 (this color)
#181B4A
oklch(25.1% 0.086 275.6)
#181B4A 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) | #00234C | 0.032 |
| Deuteranopia (no green cones) | #001E49 | 0.028 |
| Tritanopia (no blue cones) | #00262F | 0.073 |
| Achromatopsia (no color) | #202020 | 0.086 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #181B4A
#181B4A
oklch(25.1% 0.086 275.6)
- #2A2100
#2A2100
oklch(25.1% 0.051 93.9)
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 #181B4A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Indigo #1F0954 ΔE 0.042
- Navy Blue #001146 ΔE 0.049
- Oxford Blue #1B263B ΔE 0.049
- Dark #1B2431 ΔE 0.060
- Rich Black #0D1B2A ΔE 0.065
- Marine #042E60 ΔE 0.065
- Midnight Blue #191970 ΔE 0.069
- Darkblue #030764 ΔE 0.069
Use #181B4A 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.