#1B3B83
Closest named color: Twilight Blue (#0A437A). oklch(37.4% 0.127 263.4), rgb(27, 59, 131).
Aa
White text reads best on this color (10.50:1).
About this color
#1B3B83 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.127 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.030 away. White text reads best on it, at 10.50:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.127) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.99:1 |
| White text | 10.50:1 |
Values
| HEX | #1B3B83 |
| RGB | rgb(27, 59, 131) |
| HSL | hsl(222, 66%, 31%) |
| OKLCH | oklch(37.4% 0.127 263.4) |
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 #1B3B83 | 10.50:1 | AAA | Lc -98.0 | Preferred for body text |
| Black text on #1B3B83 | 1.99:1 | Fails | Lc 10.0 | Not readable |
| #1B3B83 text on white | 10.50:1 | AAA | Lc 93.9 | Preferred for body text |
| #1B3B83 text on black | 1.99:1 | Fails | Lc -8.6 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E0EAFD
oklch(93.5% 0.028 263.4)
-
Step 200
200
#C7DAFD
oklch(88.5% 0.053 262.7)
-
Step 300
300
#A1C1FF
oklch(81% 0.095 263.3)
-
Step 400
400
#6E9DFF
oklch(70.6% 0.153 263.6)
-
Step 500
500
#4881FE
oklch(63.1% 0.196 263.4)
-
Step 600
600
#2C66ED
oklch(55.6% 0.213 263.4)
-
Step 700
700
#2054CE
oklch(49.1% 0.197 263.4)
-
Step 800
800
#1C46A7
oklch(42.8% 0.163 263.4)
-
Step 900
900 (this color)
#1B3B83
oklch(37.4% 0.127 263.4)
-
Step 950
950
#11244D
oklch(27.1% 0.08 263.3)
#1B3B83 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) | #044486 | 0.026 |
| Deuteranopia (no green cones) | #003B82 | 0.017 |
| Tritanopia (no blue cones) | #004D59 | 0.100 |
| Achromatopsia (no color) | #3F3F3F | 0.127 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B3B83
#1B3B83
oklch(37.4% 0.127 263.4)
- #543C00
#543C00
oklch(37.3% 0.077 83.1)
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 #1B3B83, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.030
- Cobalt #1E488F ΔE 0.041
- Marine Blue #01386A ΔE 0.048
- Light Navy #155084 ΔE 0.060
- Dark Slate Blue #483D8B ΔE 0.064
- Sapphire #2138AB ΔE 0.067
- Blueberry #464196 ΔE 0.069
- Dusk Blue #26538D ΔE 0.072
Use #1B3B83 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.