#1B317A
Closest named color: Marine Blue (#01386A). oklch(34.4% 0.127 266.7), rgb(27, 49, 122).
Aa
White text reads best on this color (11.88:1).
About this color
#1B317A is a dark, moderately saturated blue. In OKLCH its lightness is 34%, its chroma 0.127 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.039 away. White text reads best on it, at 11.88:1.
| Hue family | Blues |
| Lightness | dark (34%) |
| Chroma | moderately saturated (0.127) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.76:1 |
| White text | 11.88:1 |
Values
| HEX | #1B317A |
| RGB | rgb(27, 49, 122) |
| HSL | hsl(226, 64%, 29%) |
| OKLCH | oklch(34.4% 0.127 266.7) |
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 #1B317A | 11.88:1 | AAA | Lc -100.4 | Preferred for body text |
| Black text on #1B317A | 1.76:1 | Fails | Lc 0.0 | Not readable |
| #1B317A text on white | 11.88:1 | AAA | Lc 96.8 | Preferred for body text |
| #1B317A text on black | 1.76:1 | 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
#F1F5FE
oklch(97% 0.013 266.7)
-
Step 100
100
#E1EAFD
oklch(93.6% 0.028 265.4)
-
Step 200
200
#C9D9FD
oklch(88.5% 0.053 266.4)
-
Step 300
300
#A5BFFF
oklch(80.9% 0.095 267.2)
-
Step 400
400
#759BFF
oklch(70.6% 0.153 266.8)
-
Step 500
500
#537EFE
oklch(63% 0.196 266.7)
-
Step 600
600
#3B63ED
oklch(55.5% 0.213 266.8)
-
Step 700
700
#2E51CE
oklch(49% 0.197 266.7)
-
Step 800
800
#2643A7
oklch(42.6% 0.164 266.7)
-
Step 900
900 (this color)
#1B317A
oklch(34.4% 0.127 266.7)
-
Step 950
950
#14234D
oklch(27% 0.08 266.3)
#1B317A 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) | #003C7C | 0.031 |
| Deuteranopia (no green cones) | #003379 | 0.019 |
| Tritanopia (no blue cones) | #004350 | 0.101 |
| Achromatopsia (no color) | #373737 | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B317A
#1B317A
oklch(34.4% 0.127 266.7)
- #493600
#493600
oklch(34.5% 0.071 86.7)
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 #1B317A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.039
- Twilight Blue #0A437A ΔE 0.050
- Marine #042E60 ΔE 0.051
- Midnight Blue #191970 ΔE 0.060
- Prussian Blue #1D3557 ΔE 0.064
- Royal #0C1793 ΔE 0.068
- Cobalt #1E488F ΔE 0.071
- Dark Slate Blue #483D8B ΔE 0.082
Use #1B317A 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.