#1B4A71
Closest named color: Twilight Blue (#0A437A). oklch(39.7% 0.083 247), rgb(27, 74, 113).
Aa
White text reads best on this color (9.27:1).
About this color
#1B4A71 is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.083 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.031 away. White text reads best on it, at 9.27:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.083) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.26:1 |
| White text | 9.27:1 |
Values
| HEX | #1B4A71 |
| RGB | rgb(27, 74, 113) |
| HSL | hsl(207, 61%, 27%) |
| OKLCH | oklch(39.7% 0.083 247) |
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 #1B4A71 | 9.27:1 | AAA | Lc -95.5 | Preferred for body text |
| Black text on #1B4A71 | 2.26:1 | Fails | Lc 12.8 | Not readable |
| #1B4A71 text on white | 9.27:1 | AAA | Lc 91.1 | Preferred for body text |
| #1B4A71 text on black | 2.26:1 | Fails | Lc -11.2 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF6
oklch(93.6% 0.018 250.6)
-
Step 200
200
#C8DCEF
oklch(88.5% 0.034 246.8)
-
Step 300
300
#A1C5E7
oklch(80.9% 0.062 247.1)
-
Step 400
400
#6BA6DC
oklch(70.6% 0.101 247.3)
-
Step 500
500
#3F8FD2
oklch(63.1% 0.128 247)
-
Step 600
600
#1578BF
oklch(55.6% 0.138 246.9)
-
Step 700
700
#0164A5
oklch(49% 0.129 247.3)
-
Step 800
800
#0B5286
oklch(42.7% 0.107 247.4)
-
Step 900
900 (this color)
#1B4A71
oklch(39.7% 0.083 247)
-
Step 950
950
#0E283F
oklch(26.9% 0.054 248)
#1B4A71 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) | #384C73 | 0.033 |
| Deuteranopia (no green cones) | #2C4370 | 0.025 |
| Tritanopia (no blue cones) | #005358 | 0.060 |
| Achromatopsia (no color) | #474747 | 0.083 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B4A71
#1B4A71
oklch(39.7% 0.083 247)
- #643D08
#643D08
oklch(39.8% 0.083 67.5)
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 #1B4A71, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.031
- Light Navy #155084 ΔE 0.033
- Deep Sea Blue #015482 ΔE 0.037
- Dark Grey Blue #29465B ΔE 0.037
- Charcoal #264653 ΔE 0.050
- Cobalt #1E488F ΔE 0.052
- Dusk Blue #26538D ΔE 0.053
- Marine Blue #01386A ΔE 0.061
Use #1B4A71 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.