#173E87
Closest named color: Twilight Blue (#0A437A). oklch(38.3% 0.13 261.5), rgb(23, 62, 135).
Aa
White text reads best on this color (10.11:1).
About this color
#173E87 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.130 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.028 away. White text reads best on it, at 10.11:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.130) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.07:1 |
| White text | 10.11:1 |
Values
| HEX | #173E87 |
| RGB | rgb(23, 62, 135) |
| HSL | hsl(219, 71%, 31%) |
| OKLCH | oklch(38.3% 0.13 261.5) |
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 #173E87 | 10.11:1 | AAA | Lc -97.1 | Preferred for body text |
| Black text on #173E87 | 2.07:1 | Fails | Lc 10.9 | Not readable |
| #173E87 text on white | 10.11:1 | AAA | Lc 93.0 | Preferred for body text |
| #173E87 text on black | 2.07:1 | Fails | Lc -9.5 | 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
#E0EAFD
oklch(93.5% 0.028 263.4)
-
Step 200
200
#C6DAFE
oklch(88.5% 0.054 262.2)
-
Step 300
300
#9EC1FF
oklch(80.8% 0.096 261.6)
-
Step 400
400
#699EFF
oklch(70.6% 0.153 261.6)
-
Step 500
500
#3F82FF
oklch(63.1% 0.198 261.5)
-
Step 600
600
#1E67EF
oklch(55.6% 0.217 261.5)
-
Step 700
700
#1055D0
oklch(49.2% 0.201 261.4)
-
Step 800
800
#1146A8
oklch(42.6% 0.167 261.5)
-
Step 900
900 (this color)
#173E87
oklch(38.3% 0.13 261.5)
-
Step 950
950
#0E244E
oklch(27% 0.082 261.8)
#173E87 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) | #08478A | 0.025 |
| Deuteranopia (no green cones) | #003D86 | 0.013 |
| Tritanopia (no blue cones) | #00505C | 0.101 |
| Achromatopsia (no color) | #424242 | 0.130 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173E87
#173E87
oklch(38.3% 0.13 261.5)
- #583E00
#583E00
oklch(38.3% 0.079 81.8)
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 #173E87, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.028
- Cobalt #1E488F ΔE 0.032
- Light Navy #155084 ΔE 0.053
- Marine Blue #01386A ΔE 0.055
- Sapphire #2138AB ΔE 0.062
- Dark Slate Blue #483D8B ΔE 0.063
- Dusk Blue #26538D ΔE 0.064
- Deep Sea Blue #015482 ΔE 0.065
Use #173E87 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.