#181B3F
Closest named color: Oxford Blue (#1B263B). oklch(24.2% 0.068 276.5), rgb(24, 27, 63).
Aa
White text reads best on this color (16.56:1).
About this color
#181B3F is a very dark, muted blue. In OKLCH its lightness is 24%, its chroma 0.068 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.039 away. White text reads best on it, at 16.56:1.
| Hue family | Blues |
| Lightness | very dark (24%) |
| Chroma | muted (0.068) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.26:1 |
| White text | 16.56:1 |
Values
| HEX | #181B3F |
| RGB | rgb(24, 27, 63) |
| HSL | hsl(235, 45%, 17%) |
| OKLCH | oklch(24.2% 0.068 276.5) |
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 #181B3F | 16.56:1 | AAA | Lc -105.9 | Preferred for body text |
| Black text on #181B3F | 1.26:1 | Fails | Lc 0.0 | Not readable |
| #181B3F text on white | 16.56:1 | AAA | Lc 103.4 | Preferred for body text |
| #181B3F text on black | 1.26:1 | 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
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E5E9FA
oklch(93.6% 0.023 275.4)
-
Step 200
200
#D1D7F7
oklch(88.5% 0.044 277.1)
-
Step 300
300
#B3BDF5
oklch(81% 0.08 276.6)
-
Step 400
400
#8C98F0
oklch(70.7% 0.129 276.7)
-
Step 500
500
#727CEA
oklch(63.1% 0.163 276.7)
-
Step 600
600
#5C62D9
oklch(55.6% 0.179 276.7)
-
Step 700
700
#4C51BC
oklch(49.2% 0.165 276.4)
-
Step 800
800
#3E4398
oklch(42.8% 0.137 276.4)
-
Step 900
900
#343979
oklch(37.6% 0.107 276.6)
-
Step 950
950 (this color)
#181B3F
oklch(24.2% 0.068 276.5)
#181B3F 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) | #092040 | 0.023 |
| Deuteranopia (no green cones) | #051D3E | 0.025 |
| Tritanopia (no blue cones) | #06232A | 0.059 |
| Achromatopsia (no color) | #1F1F1F | 0.068 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #181B3F
#181B3F
oklch(24.2% 0.068 276.5)
- #271F00
#271F00
oklch(24.2% 0.05 95.1)
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 #181B3F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.039
- Dark #1B2431 ΔE 0.045
- Rich Black #0D1B2A ΔE 0.045
- Navy Blue #001146 ΔE 0.051
- Dark Indigo #1F0954 ΔE 0.056
- Jet #212529 ΔE 0.063
- Space Cadet #2B2D42 ΔE 0.070
- Midnight Purple #280137 ΔE 0.071
Use #181B3F 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.