#173F6D
Closest named color: Twilight Blue (#0A437A). oklch(36.5% 0.091 254.1), rgb(23, 63, 109).
Aa
White text reads best on this color (10.66:1).
About this color
#173F6D is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.091 and its hue 254°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.023 away. White text reads best on it, at 10.66:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.091) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.96:1 |
| White text | 10.66:1 |
Values
| HEX | #173F6D |
| RGB | rgb(23, 63, 109) |
| HSL | hsl(212, 65%, 26%) |
| OKLCH | oklch(36.5% 0.091 254.1) |
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 #173F6D | 10.66:1 | AAA | Lc -98.4 | Preferred for body text |
| Black text on #173F6D | 1.96:1 | Fails | Lc 9.5 | Not readable |
| #173F6D text on white | 10.66:1 | AAA | Lc 94.4 | Preferred for body text |
| #173F6D text on black | 1.96:1 | Fails | Lc -8.1 | 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
#E1EBF7
oklch(93.6% 0.019 252.9)
-
Step 200
200
#C8DBF2
oklch(88.4% 0.038 253.2)
-
Step 300
300
#A3C4ED
oklch(81% 0.068 254.1)
-
Step 400
400
#6FA4E4
oklch(70.8% 0.11 253.8)
-
Step 500
500
#478BDC
oklch(63% 0.141 254.3)
-
Step 600
600
#2674C9
oklch(55.7% 0.151 253.8)
-
Step 700
700
#1860AE
oklch(49% 0.142 254.3)
-
Step 800
800
#174F8D
oklch(42.7% 0.117 254.2)
-
Step 900
900 (this color)
#173F6D
oklch(36.5% 0.091 254.1)
-
Step 950
950
#112742
oklch(27% 0.058 254.7)
#173F6D 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) | #29426F | 0.022 |
| Deuteranopia (no green cones) | #1B3B6C | 0.012 |
| Tritanopia (no blue cones) | #004A50 | 0.071 |
| Achromatopsia (no color) | #3E3E3E | 0.091 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #173F6D
#173F6D
oklch(36.5% 0.091 254.1)
- #563700
#563700
oklch(36.5% 0.077 74.1)
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 #173F6D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.023
- Marine Blue #01386A ΔE 0.028
- Prussian Blue #1D3557 ΔE 0.044
- Dark Grey Blue #29465B ΔE 0.046
- Dark Blue Grey #1F3B4D ΔE 0.055
- Charcoal #264653 ΔE 0.057
- Marine #042E60 ΔE 0.059
- Light Navy #155084 ΔE 0.059
Use #173F6D 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.