#171F5F
Closest named color: Midnight Blue (#191970). oklch(27.9% 0.113 271.4), rgb(23, 31, 95).
Aa
White text reads best on this color (15.02:1).
About this color
#171F5F is a dark, moderately saturated blue. In OKLCH its lightness is 28%, its chroma 0.113 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Midnight Blue (#191970), ΔE 0.032 away. White text reads best on it, at 15.02:1.
| Hue family | Blues |
| Lightness | dark (28%) |
| Chroma | moderately saturated (0.113) |
| Temperature | cool |
| Nearest name | Midnight Blue (#191970) |
| Black text | 1.39:1 |
| White text | 15.02:1 |
Values
| HEX | #171F5F |
| RGB | rgb(23, 31, 95) |
| HSL | hsl(233, 61%, 23%) |
| OKLCH | oklch(27.9% 0.113 271.4) |
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 #171F5F | 15.02:1 | AAA | Lc -104.4 | Preferred for body text |
| Black text on #171F5F | 1.39:1 | Fails | Lc 0.0 | Not readable |
| #171F5F text on white | 15.02:1 | AAA | Lc 101.5 | Preferred for body text |
| #171F5F text on black | 1.39:1 | 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 950.
-
Step 50
50
#F2F5FF
oklch(97.1% 0.014 272.7)
-
Step 100
100
#E2E9FF
oklch(93.5% 0.031 271.7)
-
Step 200
200
#CBD8FF
oklch(88.5% 0.056 270.7)
-
Step 300
300
#AABDFF
oklch(80.8% 0.096 271.7)
-
Step 400
400
#7F99FF
oklch(70.8% 0.152 271.3)
-
Step 500
500
#617AFF
oklch(63% 0.198 271.6)
-
Step 600
600
#4757FF
oklch(55.5% 0.245 271.3)
-
Step 700
700
#3931F9
oklch(49.1% 0.276 271.5)
-
Step 800
800
#2D2DC9
oklch(42.8% 0.229 271.3)
-
Step 900
900
#262D9E
oklch(37.8% 0.179 271.5)
-
Step 950
950 (this color)
#171F5F
oklch(27.9% 0.113 271.4)
#171F5F 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) | #002A61 | 0.032 |
| Deuteranopia (no green cones) | #00235E | 0.023 |
| Tritanopia (no blue cones) | #002F3B | 0.090 |
| Achromatopsia (no color) | #272727 | 0.113 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #171F5F
#171F5F
oklch(27.9% 0.113 271.4)
- #332700
#332700
oklch(27.9% 0.057 91)
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 #171F5F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Midnight Blue #191970 ΔE 0.032
- Marine #042E60 ΔE 0.042
- Dark Indigo #1F0954 ΔE 0.051
- Darkblue #030764 ΔE 0.058
- Dark Royal Blue #02066F ΔE 0.060
- Deep Blue #040273 ΔE 0.065
- Prussian Blue #1D3557 ΔE 0.070
- Marine Blue #01386A ΔE 0.071
Use #171F5F 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.