#173F6A
Closest named color: Marine Blue (#01386A). oklch(36.3% 0.087 252.8), rgb(23, 63, 106).
Aa
White text reads best on this color (10.73:1).
About this color
#173F6A is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.087 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.028 away. White text reads best on it, at 10.73:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.087) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.95:1 |
| White text | 10.73:1 |
Values
| HEX | #173F6A |
| RGB | rgb(23, 63, 106) |
| HSL | hsl(211, 64%, 25%) |
| OKLCH | oklch(36.3% 0.087 252.8) |
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 #173F6A | 10.73:1 | AAA | Lc -98.5 | Preferred for body text |
| Black text on #173F6A | 1.95:1 | Fails | Lc 9.3 | Not readable |
| #173F6A text on white | 10.73:1 | AAA | Lc 94.6 | Preferred for body text |
| #173F6A text on black | 1.95:1 | Fails | Lc -8.0 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF7
oklch(93.6% 0.019 252.9)
-
Step 200
200
#C9DBF1
oklch(88.5% 0.036 253.5)
-
Step 300
300
#A3C4EA
oklch(80.9% 0.065 252.2)
-
Step 400
400
#70A4E0
oklch(70.6% 0.104 252.8)
-
Step 500
500
#488CD7
oklch(63% 0.133 252.6)
-
Step 600
600
#2775C5
oklch(55.7% 0.145 252.6)
-
Step 700
700
#1962AA
oklch(49.2% 0.134 252.5)
-
Step 800
800
#18508A
oklch(42.7% 0.112 252.8)
-
Step 900
900 (this color)
#173F6A
oklch(36.3% 0.087 252.8)
-
Step 950
950
#112740
oklch(26.9% 0.055 253.1)
#173F6A 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) | #2B426C | 0.024 |
| Deuteranopia (no green cones) | #1E3A69 | 0.015 |
| Tritanopia (no blue cones) | #00494F | 0.066 |
| Achromatopsia (no color) | #3E3E3E | 0.087 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173F6A
#173F6A
oklch(36.3% 0.087 252.8)
- #563600
#563600
oklch(36.2% 0.077 72.7)
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 #173F6A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.028
- Twilight Blue #0A437A ΔE 0.028
- Prussian Blue #1D3557 ΔE 0.041
- Dark Grey Blue #29465B ΔE 0.043
- Dark Blue Grey #1F3B4D ΔE 0.050
- Charcoal #264653 ΔE 0.053
- Midnight Green #073B4C ΔE 0.055
- Marine #042E60 ΔE 0.058
Use #173F6A 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.