#1F3671
Closest named color: Marine Blue (#01386A). oklch(35% 0.106 265.3), rgb(31, 54, 113).
Aa
White text reads best on this color (11.51:1).
About this color
#1F3671 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.106 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.026 away. White text reads best on it, at 11.51:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.106) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.82:1 |
| White text | 11.51:1 |
Values
| HEX | #1F3671 |
| RGB | rgb(31, 54, 113) |
| HSL | hsl(223, 57%, 28%) |
| OKLCH | oklch(35% 0.106 265.3) |
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 #1F3671 | 11.51:1 | AAA | Lc -99.9 | Preferred for body text |
| Black text on #1F3671 | 1.82:1 | Fails | Lc 7.7 | Not readable |
| #1F3671 text on white | 11.51:1 | AAA | Lc 96.2 | Preferred for body text |
| #1F3671 text on black | 1.82:1 | 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
#CBD9F7
oklch(88.4% 0.044 265.6)
-
Step 300
300
#A8C0F5
oklch(80.9% 0.08 265.7)
-
Step 400
400
#7A9EF0
oklch(70.7% 0.127 265.3)
-
Step 500
500
#5983EB
oklch(63% 0.163 265.4)
-
Step 600
600
#406AD9
oklch(55.6% 0.177 265.4)
-
Step 700
700
#3258BC
oklch(49.1% 0.164 265.2)
-
Step 800
800
#2A4898
oklch(42.6% 0.136 265.5)
-
Step 900
900 (this color)
#1F3671
oklch(35% 0.106 265.3)
-
Step 950
950
#162447
oklch(26.9% 0.068 265.6)
#1F3671 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) | #143D73 | 0.021 |
| Deuteranopia (no green cones) | #003670 | 0.023 |
| Tritanopia (no blue cones) | #00444E | 0.086 |
| Achromatopsia (no color) | #393939 | 0.106 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F3671
#1F3671
oklch(35% 0.106 265.3)
- #4B3700
#4B3700
oklch(35% 0.072 85.8)
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 #1F3671, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.026
- Twilight Blue #0A437A ΔE 0.039
- Prussian Blue #1D3557 ΔE 0.046
- Marine #042E60 ΔE 0.047
- Cobalt #1E488F ΔE 0.068
- Dark Blue Grey #1F3B4D ΔE 0.069
- Dark Grey Blue #29465B ΔE 0.071
- Midnight Blue #191970 ΔE 0.074
Use #1F3671 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.