#173369
Closest named color: Marine Blue (#01386A). oklch(33.3% 0.101 261.9), rgb(23, 51, 105).
Aa
White text reads best on this color (12.25:1).
About this color
#173369 is a dark, moderately saturated blue. In OKLCH its lightness is 33%, its chroma 0.101 and its hue 262°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.018 away. White text reads best on it, at 12.25:1.
| Hue family | Blues |
| Lightness | dark (33%) |
| Chroma | moderately saturated (0.101) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.71:1 |
| White text | 12.25:1 |
Values
| HEX | #173369 |
| RGB | rgb(23, 51, 105) |
| HSL | hsl(220, 64%, 25%) |
| OKLCH | oklch(33.3% 0.101 261.9) |
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 #173369 | 12.25:1 | AAA | Lc -101.1 | Preferred for body text |
| Black text on #173369 | 1.71:1 | Fails | Lc 0.0 | Not readable |
| #173369 text on white | 12.25:1 | AAA | Lc 97.6 | Preferred for body text |
| #173369 text on black | 1.71:1 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EAF9
oklch(93.5% 0.022 263.2)
-
Step 200
200
#CADAF6
oklch(88.5% 0.042 261.7)
-
Step 300
300
#A6C1F2
oklch(80.8% 0.076 262.2)
-
Step 400
400
#77A0EC
oklch(70.8% 0.121 262.1)
-
Step 500
500
#5386E6
oklch(63.1% 0.155 261.9)
-
Step 600
600
#386ED4
oklch(55.7% 0.168 261.7)
-
Step 700
700
#2B5BB8
oklch(49.2% 0.156 261.9)
-
Step 800
800
#254B95
oklch(42.8% 0.129 262)
-
Step 900
900 (this color)
#173369
oklch(33.3% 0.101 261.9)
-
Step 950
950
#142545
oklch(26.9% 0.064 261.9)
#173369 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) | #14396B | 0.018 |
| Deuteranopia (no green cones) | #003268 | 0.017 |
| Tritanopia (no blue cones) | #004049 | 0.079 |
| Achromatopsia (no color) | #353535 | 0.101 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173369
#173369
oklch(33.3% 0.101 261.9)
- #483200
#483200
oklch(33.4% 0.069 81.7)
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 #173369, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.018
- Marine #042E60 ΔE 0.028
- Prussian Blue #1D3557 ΔE 0.034
- Twilight Blue #0A437A ΔE 0.052
- Dark Blue Grey #1F3B4D ΔE 0.061
- Midnight Green #073B4C ΔE 0.064
- Midnight Blue #191970 ΔE 0.066
- Space Cadet #2B2D42 ΔE 0.071
Use #173369 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.