#1B3F80
Closest named color: Twilight Blue (#0A437A). oklch(38.1% 0.118 261.1), rgb(27, 63, 128).
Aa
White text reads best on this color (10.14:1).
About this color
#1B3F80 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.118 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.019 away. White text reads best on it, at 10.14:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.118) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.06:1 |
| White text | 10.14:1 |
Values
| HEX | #1B3F80 |
| RGB | rgb(27, 63, 128) |
| HSL | hsl(219, 65%, 30%) |
| OKLCH | oklch(38.1% 0.118 261.1) |
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 #1B3F80 | 10.14:1 | AAA | Lc -97.3 | Preferred for body text |
| Black text on #1B3F80 | 2.06:1 | Fails | Lc 10.8 | Not readable |
| #1B3F80 text on white | 10.14:1 | AAA | Lc 93.2 | Preferred for body text |
| #1B3F80 text on black | 2.06:1 | Fails | Lc -9.3 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E0EAFC
oklch(93.5% 0.027 262.3)
-
Step 200
200
#C7DAFA
oklch(88.4% 0.049 260.9)
-
Step 300
300
#A1C2FA
oklch(81% 0.087 260.8)
-
Step 400
400
#6D9FF8
oklch(70.6% 0.142 261.2)
-
Step 500
500
#4684F5
oklch(63% 0.181 261.2)
-
Step 600
600
#276BE4
oklch(55.7% 0.196 261)
-
Step 700
700
#1B58C6
oklch(49.1% 0.183 261.2)
-
Step 800
800
#1849A0
oklch(42.8% 0.151 261)
-
Step 900
900 (this color)
#1B3F80
oklch(38.1% 0.118 261.1)
-
Step 950
950
#10254A
oklch(27% 0.074 260.8)
#1B3F80 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) | #194682 | 0.020 |
| Deuteranopia (no green cones) | #003D7F | 0.018 |
| Tritanopia (no blue cones) | #004F59 | 0.093 |
| Achromatopsia (no color) | #414141 | 0.118 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B3F80
#1B3F80
oklch(38.1% 0.118 261.1)
- #583D00
#583D00
oklch(38.1% 0.079 80.4)
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 #1B3F80, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.019
- Cobalt #1E488F ΔE 0.035
- Marine Blue #01386A ΔE 0.047
- Light Navy #155084 ΔE 0.049
- Deep Sea Blue #015482 ΔE 0.061
- Dusk Blue #26538D ΔE 0.062
- Dark Slate Blue #483D8B ΔE 0.063
- Blueberry #464196 ΔE 0.068
Use #1B3F80 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.