#1B317D
Closest named color: Marine Blue (#01386A). oklch(34.7% 0.132 266.9), rgb(27, 49, 125).
Aa
White text reads best on this color (11.78:1).
About this color
#1B317D is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.132 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.043 away. White text reads best on it, at 11.78:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.132) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.78:1 |
| White text | 11.78:1 |
Values
| HEX | #1B317D |
| RGB | rgb(27, 49, 125) |
| HSL | hsl(227, 64%, 30%) |
| OKLCH | oklch(34.7% 0.132 266.9) |
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 #1B317D | 11.78:1 | AAA | Lc -100.2 | Preferred for body text |
| Black text on #1B317D | 1.78:1 | Fails | Lc 7.3 | Not readable |
| #1B317D text on white | 11.78:1 | AAA | Lc 96.6 | Preferred for body text |
| #1B317D text on black | 1.78:1 | 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
#F1F5FF
oklch(97% 0.014 268.5)
-
Step 100
100
#E1EAFE
oklch(93.6% 0.029 266.4)
-
Step 200
200
#C9D9FF
oklch(88.6% 0.055 267.2)
-
Step 300
300
#A5BFFF
oklch(80.9% 0.095 267.2)
-
Step 400
400
#769BFF
oklch(70.7% 0.152 267.2)
-
Step 500
500
#537EFF
oklch(63.1% 0.197 266.8)
-
Step 600
600
#3A62F1
oklch(55.6% 0.219 266.9)
-
Step 700
700
#2D50D2
oklch(49.2% 0.204 266.8)
-
Step 800
800
#2642AA
oklch(42.7% 0.17 267.1)
-
Step 900
900 (this color)
#1B317D
oklch(34.7% 0.132 266.9)
-
Step 950
950
#14234F
oklch(27.1% 0.083 266.7)
#1B317D 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) | #003C80 | 0.031 |
| Deuteranopia (no green cones) | #00337C | 0.019 |
| Tritanopia (no blue cones) | #004452 | 0.103 |
| Achromatopsia (no color) | #383838 | 0.132 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B317D
#1B317D
oklch(34.7% 0.132 266.9)
- #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 #1B317D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.043
- Twilight Blue #0A437A ΔE 0.050
- Marine #042E60 ΔE 0.056
- Midnight Blue #191970 ΔE 0.062
- Royal #0C1793 ΔE 0.065
- Cobalt #1E488F ΔE 0.069
- Prussian Blue #1D3557 ΔE 0.069
- Sapphire #2138AB ΔE 0.080
Use #1B317D 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.