#173C70
Closest named color: Marine Blue (#01386A). oklch(36% 0.099 257.6), rgb(23, 60, 112).
Aa
White text reads best on this color (10.95:1).
About this color
#173C70 is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.099 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.023 away. White text reads best on it, at 10.95:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.099) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.91:1 |
| White text | 10.95:1 |
Values
| HEX | #173C70 |
| RGB | rgb(23, 60, 112) |
| HSL | hsl(215, 66%, 26%) |
| OKLCH | oklch(36% 0.099 257.6) |
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 #173C70 | 10.95:1 | AAA | Lc -98.9 | Preferred for body text |
| Black text on #173C70 | 1.91:1 | Fails | Lc 8.9 | Not readable |
| #173C70 text on white | 10.95:1 | AAA | Lc 95.0 | Preferred for body text |
| #173C70 text on black | 1.91:1 | Fails | Lc -7.6 | 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
#E1EBF9
oklch(93.7% 0.022 256.7)
-
Step 200
200
#C8DBF5
oklch(88.5% 0.041 256.2)
-
Step 300
300
#A3C3F1
oklch(81% 0.074 257.4)
-
Step 400
400
#70A2EA
oklch(70.7% 0.119 257.5)
-
Step 500
500
#4989E4
oklch(63.2% 0.153 257.5)
-
Step 600
600
#2A71D2
oklch(55.7% 0.165 257.5)
-
Step 700
700
#1C5EB6
oklch(49.2% 0.154 257.4)
-
Step 800
800
#1A4D93
oklch(42.7% 0.127 257.5)
-
Step 900
900 (this color)
#173C70
oklch(36% 0.099 257.6)
-
Step 950
950
#112645
oklch(27% 0.064 258.1)
#173C70 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) | #224172 | 0.020 |
| Deuteranopia (no green cones) | #10396F | 0.011 |
| Tritanopia (no blue cones) | #004850 | 0.077 |
| Achromatopsia (no color) | #3C3C3C | 0.099 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173C70
#173C70
oklch(36% 0.099 257.6)
- #533700
#533700
oklch(36% 0.075 77.1)
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 #173C70, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.023
- Twilight Blue #0A437A ΔE 0.025
- Prussian Blue #1D3557 ΔE 0.045
- Marine #042E60 ΔE 0.053
- Dark Grey Blue #29465B ΔE 0.057
- Cobalt #1E488F ΔE 0.061
- Dark Blue Grey #1F3B4D ΔE 0.061
- Light Navy #155084 ΔE 0.064
Use #173C70 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.