#173A97
Closest named color: Sapphire (#2138AB). oklch(38.8% 0.158 264.4), rgb(23, 58, 151).
Aa
White text reads best on this color (10.05:1).
About this color
#173A97 is a dark, vivid blue. In OKLCH its lightness is 39%, its chroma 0.158 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.034 away. White text reads best on it, at 10.05:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | vivid (0.158) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.08:1 |
| White text | 10.05:1 |
Values
| HEX | #173A97 |
| RGB | rgb(23, 58, 151) |
| HSL | hsl(224, 74%, 34%) |
| OKLCH | oklch(38.8% 0.158 264.4) |
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 #173A97 | 10.05:1 | AAA | Lc -96.9 | Preferred for body text |
| Black text on #173A97 | 2.08:1 | Fails | Lc 11.3 | Not readable |
| #173A97 text on white | 10.05:1 | AAA | Lc 92.7 | Preferred for body text |
| #173A97 text on black | 2.08:1 | Fails | Lc -9.8 | 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 900.
-
Step 50
50
#F1F6FF
oklch(97.2% 0.013 262.4)
-
Step 100
100
#E0EAFF
oklch(93.6% 0.03 265.3)
-
Step 200
200
#C7D9FF
oklch(88.4% 0.056 265.2)
-
Step 300
300
#A2C0FF
oklch(80.9% 0.096 264.7)
-
Step 400
400
#709DFF
oklch(70.7% 0.152 264.2)
-
Step 500
500
#4B80FF
oklch(63.1% 0.197 264.4)
-
Step 600
600
#255FFF
oklch(55.6% 0.244 264.3)
-
Step 700
700
#1448E8
oklch(49.1% 0.245 264.4)
-
Step 800
800
#123DBB
oklch(42.7% 0.202 264.3)
-
Step 900
900 (this color)
#173A97
oklch(38.8% 0.158 264.4)
-
Step 950
950
#0C2156
oklch(26.9% 0.1 264.3)
#173A97 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) | #00489A | 0.035 |
| Deuteranopia (no green cones) | #003C95 | 0.012 |
| Tritanopia (no blue cones) | #005262 | 0.123 |
| Achromatopsia (no color) | #424242 | 0.158 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173A97
#173A97
oklch(38.8% 0.158 264.4)
- #584000
#584000
oklch(38.7% 0.079 84.4)
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 #173A97, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.034
- Cobalt #1E488F ΔE 0.042
- Twilight Blue #0A437A ΔE 0.056
- Blueberry #464196 ΔE 0.064
- Dark Slate Blue #483D8B ΔE 0.068
- Light Navy #155084 ΔE 0.071
- Royal #0C1793 ΔE 0.074
- Indigo Blue #3A18B1 ΔE 0.075
Use #173A97 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.