#173D83
Closest named color: Twilight Blue (#0A437A). oklch(37.7% 0.126 261.3), rgb(23, 61, 131).
Aa
White text reads best on this color (10.33:1).
About this color
#173D83 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.126 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.025 away. White text reads best on it, at 10.33:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.126) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.03:1 |
| White text | 10.33:1 |
Values
| HEX | #173D83 |
| RGB | rgb(23, 61, 131) |
| HSL | hsl(219, 70%, 30%) |
| OKLCH | oklch(37.7% 0.126 261.3) |
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 #173D83 | 10.33:1 | AAA | Lc -97.6 | Preferred for body text |
| Black text on #173D83 | 2.03:1 | Fails | Lc 10.4 | Not readable |
| #173D83 text on white | 10.33:1 | AAA | Lc 93.5 | Preferred for body text |
| #173D83 text on black | 2.03:1 | Fails | Lc -9.0 | 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 900.
-
Step 50
50
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E0EAFD
oklch(93.5% 0.028 263.4)
-
Step 200
200
#C6DAFD
oklch(88.5% 0.053 261.7)
-
Step 300
300
#9FC1FE
oklch(80.8% 0.094 261.9)
-
Step 400
400
#6A9FFE
oklch(70.8% 0.151 261.3)
-
Step 500
500
#4183FC
oklch(63.1% 0.193 261.3)
-
Step 600
600
#2169EB
oklch(55.7% 0.209 261.2)
-
Step 700
700
#1456CD
oklch(49.2% 0.195 261.3)
-
Step 800
800
#1347A5
oklch(42.6% 0.161 261.2)
-
Step 900
900 (this color)
#173D83
oklch(37.7% 0.126 261.3)
-
Step 950
950
#0E244D
oklch(26.9% 0.081 261.5)
#173D83 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) | #0D4586 | 0.022 |
| Deuteranopia (no green cones) | #003C82 | 0.014 |
| Tritanopia (no blue cones) | #004E5A | 0.097 |
| Achromatopsia (no color) | #404040 | 0.126 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173D83
#173D83
oklch(37.7% 0.126 261.3)
- #563C00
#563C00
oklch(37.6% 0.078 81.1)
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 #173D83, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.025
- Cobalt #1E488F ΔE 0.037
- Marine Blue #01386A ΔE 0.048
- Light Navy #155084 ΔE 0.055
- Dark Slate Blue #483D8B ΔE 0.065
- Deep Sea Blue #015482 ΔE 0.067
- Dusk Blue #26538D ΔE 0.068
- Sapphire #2138AB ΔE 0.068
Use #173D83 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.