#171837
Closest named color: Rich Black (#0D1B2A). oklch(22.7% 0.059 279.2), rgb(23, 24, 55).
Aa
White text reads best on this color (17.18:1).
About this color
#171837 is a very dark, muted blue. In OKLCH its lightness is 23%, its chroma 0.059 and its hue 279°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.034 away. White text reads best on it, at 17.18:1.
| Hue family | Blues |
| Lightness | very dark (23%) |
| Chroma | muted (0.059) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.22:1 |
| White text | 17.18:1 |
Values
| HEX | #171837 |
| RGB | rgb(23, 24, 55) |
| HSL | hsl(238, 41%, 15%) |
| OKLCH | oklch(22.7% 0.059 279.2) |
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 #171837 | 17.18:1 | AAA | Lc -106.3 | Preferred for body text |
| Black text on #171837 | 1.22:1 | Fails | Lc 0.0 | Not readable |
| #171837 text on white | 17.18:1 | AAA | Lc 104.0 | Preferred for body text |
| #171837 text on black | 1.22:1 | 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
#F4F5FC
oklch(97.1% 0.009 279.7)
-
Step 100
100
#E7E9F8
oklch(93.7% 0.02 279.9)
-
Step 200
200
#D3D7F3
oklch(88.5% 0.039 279.1)
-
Step 300
300
#B6BDEE
oklch(81% 0.07 278.4)
-
Step 400
400
#9299E5
oklch(70.7% 0.111 279.1)
-
Step 500
500
#797EDE
oklch(63.2% 0.143 279.2)
-
Step 600
600
#6365CB
oklch(55.7% 0.154 279.3)
-
Step 700
700
#5253B0
oklch(49.1% 0.145 279.2)
-
Step 800
800
#43448E
oklch(42.6% 0.12 279.5)
-
Step 900
900
#383A72
oklch(37.7% 0.094 279.3)
-
Step 950
950 (this color)
#171837
oklch(22.7% 0.059 279.2)
#171837 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) | #0A1D38 | 0.022 |
| Deuteranopia (no green cones) | #081A36 | 0.022 |
| Tritanopia (no blue cones) | #0B1F24 | 0.053 |
| Achromatopsia (no color) | #1B1B1B | 0.059 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #171837
#171837
oklch(22.7% 0.059 279.2)
- #221C00
#221C00
oklch(22.7% 0.047 98)
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 #171837, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.034
- Dark #1B2431 ΔE 0.046
- Oxford Blue #1B263B ΔE 0.047
- Navy Blue #001146 ΔE 0.051
- Jet #212529 ΔE 0.062
- Dark Indigo #1F0954 ΔE 0.065
- Midnight Purple #280137 ΔE 0.065
- Very Dark Purple #2A0134 ΔE 0.067
Use #171837 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.