#173578
Closest named color: Marine Blue (#01386A). oklch(35% 0.12 263.3), rgb(23, 53, 120).
Aa
White text reads best on this color (11.55:1).
About this color
#173578 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.120 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.030 away. White text reads best on it, at 11.55:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.120) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.81:1 |
| White text | 11.55:1 |
Values
| HEX | #173578 |
| RGB | rgb(23, 53, 120) |
| HSL | hsl(221, 68%, 28%) |
| OKLCH | oklch(35% 0.12 263.3) |
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 #173578 | 11.55:1 | AAA | Lc -99.9 | Preferred for body text |
| Black text on #173578 | 1.81:1 | Fails | Lc 7.7 | Not readable |
| #173578 text on white | 11.55:1 | AAA | Lc 96.2 | Preferred for body text |
| #173578 text on black | 1.81:1 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E1EAFC
oklch(93.6% 0.026 264.4)
-
Step 200
200
#C8DAFB
oklch(88.5% 0.05 262.6)
-
Step 300
300
#A2C1FC
oklch(80.9% 0.091 263)
-
Step 400
400
#719EFA
oklch(70.7% 0.144 263.4)
-
Step 500
500
#4C82F7
oklch(63% 0.184 263.4)
-
Step 600
600
#3068E6
oklch(55.5% 0.201 263.3)
-
Step 700
700
#2456C8
oklch(49.1% 0.186 263.3)
-
Step 800
800
#1F47A2
oklch(42.7% 0.154 263.4)
-
Step 900
900 (this color)
#173578
oklch(35% 0.12 263.3)
-
Step 950
950
#12244B
oklch(26.9% 0.076 263.5)
#173578 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) | #013E7A | 0.026 |
| Deuteranopia (no green cones) | #003577 | 0.015 |
| Tritanopia (no blue cones) | #004551 | 0.093 |
| Achromatopsia (no color) | #393939 | 0.120 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173578
#173578
oklch(35% 0.12 263.3)
- #4C3600
#4C3600
oklch(34.9% 0.072 83.2)
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 #173578, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.030
- Twilight Blue #0A437A ΔE 0.039
- Marine #042E60 ΔE 0.050
- Prussian Blue #1D3557 ΔE 0.058
- Cobalt #1E488F ΔE 0.065
- Midnight Blue #191970 ΔE 0.069
- Royal #0C1793 ΔE 0.077
- Light Navy #155084 ΔE 0.079
Use #173578 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.