#171B43
Closest named color: Oxford Blue (#1B263B). oklch(24.4% 0.075 275.1), rgb(23, 27, 67).
Aa
White text reads best on this color (16.48:1).
About this color
#171B43 is a very dark, moderately saturated blue. In OKLCH its lightness is 24%, its chroma 0.075 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.043 away. White text reads best on it, at 16.48:1.
| Hue family | Blues |
| Lightness | very dark (24%) |
| Chroma | moderately saturated (0.075) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.27:1 |
| White text | 16.48:1 |
Values
| HEX | #171B43 |
| RGB | rgb(23, 27, 67) |
| HSL | hsl(235, 49%, 18%) |
| OKLCH | oklch(24.4% 0.075 275.1) |
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 #171B43 | 16.48:1 | AAA | Lc -105.8 | Preferred for body text |
| Black text on #171B43 | 1.27:1 | Fails | Lc 0.0 | Not readable |
| #171B43 text on white | 16.48:1 | AAA | Lc 103.3 | Preferred for body text |
| #171B43 text on black | 1.27:1 | 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
#F3F5FE
oklch(97.1% 0.012 276.1)
-
Step 100
100
#E4E9FC
oklch(93.6% 0.026 274.1)
-
Step 200
200
#CFD7FA
oklch(88.4% 0.049 275.2)
-
Step 300
300
#B0BDFA
oklch(81% 0.088 275)
-
Step 400
400
#8898F8
oklch(70.8% 0.141 275)
-
Step 500
500
#6D7AF4
oklch(63% 0.181 275.4)
-
Step 600
600
#5760E3
oklch(55.6% 0.196 275.1)
-
Step 700
700
#484EC5
oklch(49.1% 0.182 275.2)
-
Step 800
800
#3B41A0
oklch(42.8% 0.151 275.2)
-
Step 900
900
#31387F
oklch(37.7% 0.119 274.9)
-
Step 950
950 (this color)
#171B43
oklch(24.4% 0.075 275.1)
#171B43 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) | #042144 | 0.026 |
| Deuteranopia (no green cones) | #001D42 | 0.028 |
| Tritanopia (no blue cones) | #00242C | 0.064 |
| Achromatopsia (no color) | #1F1F1F | 0.075 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #171B43
#171B43
oklch(24.4% 0.075 275.1)
- #282000
#282000
oklch(24.6% 0.05 95.4)
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 #171B43, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.043
- Navy Blue #001146 ΔE 0.048
- Dark Indigo #1F0954 ΔE 0.051
- Dark #1B2431 ΔE 0.051
- Rich Black #0D1B2A ΔE 0.052
- Jet #212529 ΔE 0.069
- Night Blue #040348 ΔE 0.071
- Space Cadet #2B2D42 ΔE 0.071
Use #171B43 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.