#173A6D
Closest named color: Marine Blue (#01386A). oklch(35.3% 0.097 258.1), rgb(23, 58, 109).
Aa
White text reads best on this color (11.27:1).
About this color
#173A6D is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.097 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.017 away. White text reads best on it, at 11.27:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.097) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.86:1 |
| White text | 11.27:1 |
Values
| HEX | #173A6D |
| RGB | rgb(23, 58, 109) |
| HSL | hsl(216, 65%, 26%) |
| OKLCH | oklch(35.3% 0.097 258.1) |
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 #173A6D | 11.27:1 | AAA | Lc -99.5 | Preferred for body text |
| Black text on #173A6D | 1.86:1 | Fails | Lc 8.2 | Not readable |
| #173A6D text on white | 11.27:1 | AAA | Lc 95.7 | Preferred for body text |
| #173A6D text on black | 1.86:1 | 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 900.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C9DBF5
oklch(88.6% 0.041 257.5)
-
Step 300
300
#A4C3F0
oklch(81% 0.072 257.6)
-
Step 400
400
#72A2E9
oklch(70.7% 0.117 258)
-
Step 500
500
#4C89E2
oklch(63.2% 0.149 257.9)
-
Step 600
600
#2E70D0
oklch(55.5% 0.163 258.2)
-
Step 700
700
#215EB4
oklch(49.2% 0.15 258)
-
Step 800
800
#1D4D92
oklch(42.7% 0.125 258.1)
-
Step 900
900 (this color)
#173A6D
oklch(35.3% 0.097 258.1)
-
Step 950
950
#122644
oklch(26.9% 0.062 258.3)
#173A6D 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) | #203F6F | 0.019 |
| Deuteranopia (no green cones) | #0F376C | 0.012 |
| Tritanopia (no blue cones) | #00464E | 0.075 |
| Achromatopsia (no color) | #3B3B3B | 0.097 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173A6D
#173A6D
oklch(35.3% 0.097 258.1)
- #503500
#503500
oklch(35.2% 0.074 77.3)
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 #173A6D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.017
- Twilight Blue #0A437A ΔE 0.032
- Prussian Blue #1D3557 ΔE 0.039
- Marine #042E60 ΔE 0.046
- Dark Blue Grey #1F3B4D ΔE 0.058
- Dark Grey Blue #29465B ΔE 0.059
- Midnight Green #073B4C ΔE 0.062
- Cobalt #1E488F ΔE 0.068
Use #173A6D 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.