#17173B
Closest named color: Rich Black (#0D1B2A). oklch(22.8% 0.068 279.6), rgb(23, 23, 59).
Aa
White text reads best on this color (17.18:1).
About this color
#17173B is a very dark, muted blue. In OKLCH its lightness is 23%, its chroma 0.068 and its hue 280°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.041 away. White text reads best on it, at 17.18:1.
| Hue family | Blues |
| Lightness | very dark (23%) |
| Chroma | muted (0.068) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.22:1 |
| White text | 17.18:1 |
Values
| HEX | #17173B |
| RGB | rgb(23, 23, 59) |
| HSL | hsl(240, 44%, 16%) |
| OKLCH | oklch(22.8% 0.068 279.6) |
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 #17173B | 17.18:1 | AAA | Lc -106.3 | Preferred for body text |
| Black text on #17173B | 1.22:1 | Fails | Lc 0.0 | Not readable |
| #17173B text on white | 17.18:1 | AAA | Lc 103.9 | Preferred for body text |
| #17173B 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
#F4F5FD
oklch(97.2% 0.011 280.5)
-
Step 100
100
#E6E9FA
oklch(93.7% 0.023 277.9)
-
Step 200
200
#D2D7F7
oklch(88.5% 0.044 278.4)
-
Step 300
300
#B5BCF4
oklch(80.9% 0.079 278.9)
-
Step 400
400
#9197EF
oklch(70.8% 0.128 279.6)
-
Step 500
500
#787AE9
oklch(63.1% 0.163 279.8)
-
Step 600
600
#6260D8
oklch(55.6% 0.179 279.6)
-
Step 700
700
#524FBB
oklch(49.2% 0.165 279.7)
-
Step 800
800
#434197
oklch(42.7% 0.137 279.9)
-
Step 900
900
#383878
oklch(37.7% 0.106 280)
-
Step 950
950 (this color)
#17173B
oklch(22.8% 0.068 279.6)
#17173B 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) | #041D3C | 0.029 |
| Deuteranopia (no green cones) | #021A3A | 0.029 |
| Tritanopia (no blue cones) | #081F26 | 0.058 |
| Achromatopsia (no color) | #1B1B1B | 0.068 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #17173B
#17173B
oklch(22.8% 0.068 279.6)
- #221D00
#221D00
oklch(22.9% 0.048 100.3)
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 #17173B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.041
- Navy Blue #001146 ΔE 0.046
- Oxford Blue #1B263B ΔE 0.051
- Dark #1B2431 ΔE 0.052
- Dark Indigo #1F0954 ΔE 0.056
- Midnight Purple #280137 ΔE 0.062
- Very Dark Purple #2A0134 ΔE 0.065
- Night Blue #040348 ΔE 0.067
Use #17173B 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.