#173B64
Closest named color: Marine Blue (#01386A). oklch(34.9% 0.083 253.7), rgb(23, 59, 100).
Aa
White text reads best on this color (11.37:1).
About this color
#173B64 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.083 and its hue 254°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.021 away. White text reads best on it, at 11.37:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.083) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.84:1 |
| White text | 11.37:1 |
Values
| HEX | #173B64 |
| RGB | rgb(23, 59, 100) |
| HSL | hsl(212, 63%, 24%) |
| OKLCH | oklch(34.9% 0.083 253.7) |
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 #173B64 | 11.37:1 | AAA | Lc -99.7 | Preferred for body text |
| Black text on #173B64 | 1.84:1 | Fails | Lc 7.9 | Not readable |
| #173B64 text on white | 11.37:1 | AAA | Lc 96.0 | Preferred for body text |
| #173B64 text on black | 1.84:1 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E2EBF6
oklch(93.7% 0.018 253.3)
-
Step 200
200
#CADBF0
oklch(88.5% 0.034 253.7)
-
Step 300
300
#A5C3E9
oklch(80.8% 0.063 254.5)
-
Step 400
400
#74A4DD
oklch(70.7% 0.099 253.3)
-
Step 500
500
#4E8CD4
oklch(63.1% 0.127 253.5)
-
Step 600
600
#3074C1
oklch(55.5% 0.138 253.9)
-
Step 700
700
#2261A7
oklch(49% 0.129 253.9)
-
Step 800
800
#1E5087
oklch(42.7% 0.106 253.3)
-
Step 900
900 (this color)
#173B64
oklch(34.9% 0.083 253.7)
-
Step 950
950
#13273F
oklch(26.9% 0.052 254)
#173B64 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) | #283E66 | 0.022 |
| Deuteranopia (no green cones) | #1C3763 | 0.012 |
| Tritanopia (no blue cones) | #00454A | 0.065 |
| Achromatopsia (no color) | #3A3A3A | 0.083 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173B64
#173B64
oklch(34.9% 0.083 253.7)
- #513300
#513300
oklch(34.9% 0.074 73.3)
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 #173B64, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.021
- Prussian Blue #1D3557 ΔE 0.026
- Twilight Blue #0A437A ΔE 0.041
- Dark Blue Grey #1F3B4D ΔE 0.041
- Marine #042E60 ΔE 0.045
- Midnight Green #073B4C ΔE 0.046
- Dark Grey Blue #29465B ΔE 0.048
- Charcoal #264653 ΔE 0.055
Use #173B64 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.