#1B4783
Closest named color: Cobalt (#1E488F). oklch(40.2% 0.112 257.2), rgb(27, 71, 131).
Aa
White text reads best on this color (9.22:1).
About this color
#1B4783 is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.112 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.020 away. White text reads best on it, at 9.22:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.112) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.27:1 |
| White text | 9.22:1 |
Values
| HEX | #1B4783 |
| RGB | rgb(27, 71, 131) |
| HSL | hsl(215, 66%, 31%) |
| OKLCH | oklch(40.2% 0.112 257.2) |
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 #1B4783 | 9.22:1 | AAA | Lc -95.3 | Preferred for body text |
| Black text on #1B4783 | 2.27:1 | Fails | Lc 13.1 | Not readable |
| #1B4783 text on white | 9.22:1 | AAA | Lc 90.9 | Preferred for body text |
| #1B4783 text on black | 2.27:1 | Fails | Lc -11.4 | 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E0EBFA
oklch(93.6% 0.024 256.1)
-
Step 200
200
#C6DBF8
oklch(88.5% 0.046 256.5)
-
Step 300
300
#9EC3F7
oklch(80.9% 0.084 256.9)
-
Step 400
400
#68A2F3
oklch(70.7% 0.134 256.9)
-
Step 500
500
#3D88EF
oklch(63.2% 0.172 257.2)
-
Step 600
600
#156FDD
oklch(55.6% 0.186 257.1)
-
Step 700
700
#045CC0
oklch(49.1% 0.173 257.2)
-
Step 800
800
#0B4C9B
oklch(42.8% 0.143 257)
-
Step 900
900 (this color)
#1B4783
oklch(40.2% 0.112 257.2)
-
Step 950
950
#0D2648
oklch(27% 0.07 257)
#1B4783 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) | #284D85 | 0.023 |
| Deuteranopia (no green cones) | #134382 | 0.014 |
| Tritanopia (no blue cones) | #00555E | 0.086 |
| Achromatopsia (no color) | #474747 | 0.112 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B4783
#1B4783
oklch(40.2% 0.112 257.2)
- #614100
#614100
oklch(40.2% 0.084 77.1)
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 #1B4783, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.020
- Twilight Blue #0A437A ΔE 0.023
- Light Navy #155084 ΔE 0.026
- Deep Sea Blue #015482 ΔE 0.039
- Dusk Blue #26538D ΔE 0.040
- Dark Slate Blue #483D8B ΔE 0.062
- Light Navy Blue #2E5A88 ΔE 0.062
- Blueberry #464196 ΔE 0.063
Use #1B4783 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.