#00173B
Closest named color: Navy Blue (#001146). oklch(21.3% 0.077 257.3), rgb(0, 23, 59).
Aa
White text reads best on this color (17.71:1).
About this color
#00173B is a very dark, moderately saturated blue. In OKLCH its lightness is 21%, its chroma 0.077 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Navy Blue (#001146), ΔE 0.027 away. White text reads best on it, at 17.71:1.
| Hue family | Blues |
| Lightness | very dark (21%) |
| Chroma | moderately saturated (0.077) |
| Temperature | cool |
| Nearest name | Navy Blue (#001146) |
| Black text | 1.18:1 |
| White text | 17.71:1 |
Values
| HEX | #00173B |
| RGB | rgb(0, 23, 59) |
| HSL | hsl(217, 100%, 12%) |
| OKLCH | oklch(21.3% 0.077 257.3) |
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 #00173B | 17.71:1 | AAA | Lc -106.5 | Preferred for body text |
| Black text on #00173B | 1.18:1 | Fails | Lc 0.0 | Not readable |
| #00173B text on white | 17.71:1 | AAA | Lc 104.2 | Preferred for body text |
| #00173B text on black | 1.18:1 | 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
#F0F6FE
oklch(97.1% 0.012 255.5)
-
Step 100
100
#DFEBFC
oklch(93.6% 0.026 257)
-
Step 200
200
#C5DBFB
oklch(88.5% 0.05 257.7)
-
Step 300
300
#9CC3FB
oklch(80.9% 0.09 257.4)
-
Step 400
400
#63A1F9
oklch(70.6% 0.145 257.3)
-
Step 500
500
#3487F7
oklch(63.2% 0.185 257.3)
-
Step 600
600
#006DE5
oklch(55.6% 0.201 257.4)
-
Step 700
700
#005BC2
oklch(49% 0.177 257.5)
-
Step 800
800
#004AA1
oklch(42.6% 0.155 257.6)
-
Step 900
900
#0E3F80
oklch(37.7% 0.121 257.5)
-
Step 950
950 (this color)
#00173B
oklch(21.3% 0.077 257.3)
#00173B 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) | #001B3C | 0.013 |
| Deuteranopia (no green cones) | #00163A | 0.004 |
| Tritanopia (no blue cones) | #002026 | 0.057 |
| Achromatopsia (no color) | #181818 | 0.077 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #00173B
#00173B
oklch(21.3% 0.077 257.3)
- #241600
#241600
oklch(21.3% 0.044 78.3)
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 #00173B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Navy Blue #001146 ΔE 0.027
- Rich Black #0D1B2A ΔE 0.042
- Night Blue #040348 ΔE 0.052
- Dark Navy #000435 ΔE 0.057
- Oxford Blue #1B263B ΔE 0.066
- Dark #1B2431 ΔE 0.067
- Very Dark Blue #000133 ΔE 0.069
- Rich Navy #001219 ΔE 0.069
Use #00173B 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.