#1F3571
Closest named color: Marine Blue (#01386A). oklch(34.8% 0.107 265.9), rgb(31, 53, 113).
Aa
White text reads best on this color (11.62:1).
About this color
#1F3571 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.107 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.027 away. White text reads best on it, at 11.62:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.107) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.80:1 |
| White text | 11.62:1 |
Values
| HEX | #1F3571 |
| RGB | rgb(31, 53, 113) |
| HSL | hsl(224, 57%, 28%) |
| OKLCH | oklch(34.8% 0.107 265.9) |
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 #1F3571 | 11.62:1 | AAA | Lc -100.1 | Preferred for body text |
| Black text on #1F3571 | 1.80:1 | Fails | Lc 7.5 | Not readable |
| #1F3571 text on white | 11.62:1 | AAA | Lc 96.4 | Preferred for body text |
| #1F3571 text on black | 1.80:1 | 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
#F2F5FD
oklch(97% 0.011 269.6)
-
Step 100
100
#E2EAFA
oklch(93.6% 0.023 264.5)
-
Step 200
200
#CBD9F8
oklch(88.5% 0.045 266.2)
-
Step 300
300
#A8C0F6
oklch(80.9% 0.081 266)
-
Step 400
400
#7A9EF1
oklch(70.8% 0.129 265.5)
-
Step 500
500
#5A83EC
oklch(63.2% 0.164 265.8)
-
Step 600
600
#416ADA
oklch(55.7% 0.178 265.7)
-
Step 700
700
#3357BE
oklch(49.1% 0.167 265.9)
-
Step 800
800
#2B4899
oklch(42.7% 0.137 265.9)
-
Step 900
900 (this color)
#1F3571
oklch(34.8% 0.107 265.9)
-
Step 950
950
#162447
oklch(26.9% 0.068 265.6)
#1F3571 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) | #113D73 | 0.024 |
| Deuteranopia (no green cones) | #003570 | 0.023 |
| Tritanopia (no blue cones) | #00434D | 0.087 |
| Achromatopsia (no color) | #393939 | 0.107 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F3571
#1F3571
oklch(34.8% 0.107 265.9)
- #4A3700
#4A3700
oklch(34.8% 0.071 87)
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 #1F3571, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.027
- Twilight Blue #0A437A ΔE 0.041
- Marine #042E60 ΔE 0.045
- Prussian Blue #1D3557 ΔE 0.046
- Dark Blue Grey #1F3B4D ΔE 0.070
- Cobalt #1E488F ΔE 0.070
- Midnight Blue #191970 ΔE 0.071
- Dark Grey Blue #29465B ΔE 0.073
Use #1F3571 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.