#1B3888
Closest named color: Twilight Blue (#0A437A). oklch(37.2% 0.138 265.1), rgb(27, 56, 136).
Aa
White text reads best on this color (10.67:1).
About this color
#1B3888 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.138 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.041 away. White text reads best on it, at 10.67:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.138) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.96:1 |
| White text | 10.67:1 |
Values
| HEX | #1B3888 |
| RGB | rgb(27, 56, 136) |
| HSL | hsl(224, 67%, 32%) |
| OKLCH | oklch(37.2% 0.138 265.1) |
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 #1B3888 | 10.67:1 | AAA | Lc -98.2 | Preferred for body text |
| Black text on #1B3888 | 1.96:1 | Fails | Lc 9.7 | Not readable |
| #1B3888 text on white | 10.67:1 | AAA | Lc 94.2 | Preferred for body text |
| #1B3888 text on black | 1.96:1 | Fails | Lc -8.3 | 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
#F1F6FF
oklch(97.2% 0.013 262.4)
-
Step 100
100
#E0EAFF
oklch(93.6% 0.03 265.3)
-
Step 200
200
#C7D9FF
oklch(88.4% 0.056 265.2)
-
Step 300
300
#A3C0FF
oklch(80.9% 0.095 265.2)
-
Step 400
400
#729CFF
oklch(70.6% 0.153 265.4)
-
Step 500
500
#4D7FFF
oklch(63% 0.198 265.1)
-
Step 600
600
#2F61F7
oklch(55.5% 0.23 265.2)
-
Step 700
700
#234FD8
oklch(49.2% 0.215 265.1)
-
Step 800
800
#1D42AE
oklch(42.7% 0.177 265)
-
Step 900
900 (this color)
#1B3888
oklch(37.2% 0.138 265.1)
-
Step 950
950
#112351
oklch(27.2% 0.088 265)
#1B3888 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) | #00438B | 0.030 |
| Deuteranopia (no green cones) | #003986 | 0.017 |
| Tritanopia (no blue cones) | #004C5A | 0.108 |
| Achromatopsia (no color) | #3E3E3E | 0.139 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B3888
#1B3888
oklch(37.2% 0.138 265.1)
- #533C00
#533C00
oklch(37.2% 0.076 84.2)
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 #1B3888, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.041
- Cobalt #1E488F ΔE 0.045
- Marine Blue #01386A ΔE 0.056
- Sapphire #2138AB ΔE 0.058
- Dark Slate Blue #483D8B ΔE 0.065
- Light Navy #155084 ΔE 0.069
- Blueberry #464196 ΔE 0.069
- Royal #0C1793 ΔE 0.073
Use #1B3888 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.