#171F40
Closest named color: Oxford Blue (#1B263B). oklch(25.1% 0.063 271), rgb(23, 31, 64).
Aa
White text reads best on this color (16.07:1).
About this color
#171F40 is a dark, muted blue. In OKLCH its lightness is 25%, its chroma 0.063 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.028 away. White text reads best on it, at 16.07:1.
| Hue family | Blues |
| Lightness | dark (25%) |
| Chroma | muted (0.063) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.30:1 |
| White text | 16.07:1 |
Values
| HEX | #171F40 |
| RGB | rgb(23, 31, 64) |
| HSL | hsl(228, 47%, 17%) |
| OKLCH | oklch(25.1% 0.063 271) |
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 #171F40 | 16.07:1 | AAA | Lc -105.5 | Preferred for body text |
| Black text on #171F40 | 1.30:1 | Fails | Lc 0.0 | Not readable |
| #171F40 text on white | 16.07:1 | AAA | Lc 102.9 | Preferred for body text |
| #171F40 text on black | 1.30:1 | 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
#F3F5FC
oklch(97.1% 0.01 273.4)
-
Step 100
100
#E4E9F9
oklch(93.5% 0.022 272.1)
-
Step 200
200
#CFD8F6
oklch(88.5% 0.042 272.3)
-
Step 300
300
#AEBFF2
oklch(80.9% 0.075 270.3)
-
Step 400
400
#859CEB
oklch(70.7% 0.119 270.8)
-
Step 500
500
#6881E5
oklch(63.1% 0.153 270.9)
-
Step 600
600
#5168D3
oklch(55.6% 0.166 271)
-
Step 700
700
#4256B7
oklch(49.1% 0.154 270.9)
-
Step 800
800
#364794
oklch(42.7% 0.128 270.8)
-
Step 900
900
#2F3C76
oklch(37.7% 0.1 271.4)
-
Step 950
950 (this color)
#171F40
oklch(25.1% 0.063 271)
#171F40 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) | #102341 | 0.015 |
| Deuteranopia (no green cones) | #0B1F3F | 0.016 |
| Tritanopia (no blue cones) | #02262C | 0.056 |
| Achromatopsia (no color) | #212121 | 0.063 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #171F40
#171F40
oklch(25.1% 0.063 271)
- #2B2100
#2B2100
oklch(25.2% 0.052 92.1)
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 #171F40, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.028
- Dark #1B2431 ΔE 0.037
- Rich Black #0D1B2A ΔE 0.047
- Jet #212529 ΔE 0.056
- Navy Blue #001146 ΔE 0.058
- Space Cadet #2B2D42 ΔE 0.060
- Dark Indigo #1F0954 ΔE 0.064
- Marine #042E60 ΔE 0.069
Use #171F40 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.