#1B4584
Closest named color: Cobalt (#1E488F). oklch(39.8% 0.116 258.6), rgb(27, 69, 132).
Aa
White text reads best on this color (9.41:1).
About this color
#1B4584 is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.116 and its hue 259°. 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 9.41:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.116) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.23:1 |
| White text | 9.41:1 |
Values
| HEX | #1B4584 |
| RGB | rgb(27, 69, 132) |
| HSL | hsl(216, 66%, 31%) |
| OKLCH | oklch(39.8% 0.116 258.6) |
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 #1B4584 | 9.41:1 | AAA | Lc -95.7 | Preferred for body text |
| Black text on #1B4584 | 2.23:1 | Fails | Lc 12.6 | Not readable |
| #1B4584 text on white | 9.41:1 | AAA | Lc 91.4 | Preferred for body text |
| #1B4584 text on black | 2.23:1 | Fails | Lc -11.0 | 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
#E0EBFB
oklch(93.7% 0.025 257.6)
-
Step 200
200
#C6DBFA
oklch(88.6% 0.048 258)
-
Step 300
300
#9FC2F9
oklch(80.8% 0.087 259.3)
-
Step 400
400
#69A1F6
oklch(70.7% 0.139 258.5)
-
Step 500
500
#3F86F2
oklch(63% 0.177 258.8)
-
Step 600
600
#1A6DE1
oklch(55.6% 0.193 258.6)
-
Step 700
700
#0B5AC4
oklch(49.1% 0.18 258.7)
-
Step 800
800
#0F4A9E
oklch(42.6% 0.149 258.8)
-
Step 900
900 (this color)
#1B4584
oklch(39.8% 0.116 258.6)
-
Step 950
950
#0E254A
oklch(26.9% 0.075 259.5)
#1B4584 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) | #234B86 | 0.020 |
| Deuteranopia (no green cones) | #094283 | 0.015 |
| Tritanopia (no blue cones) | #00545E | 0.089 |
| Achromatopsia (no color) | #464646 | 0.116 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B4584
#1B4584
oklch(39.8% 0.116 258.6)
- #5F4100
#5F4100
oklch(39.9% 0.083 79)
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 #1B4584, 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 0.022
- Light Navy #155084 ΔE 0.032
- Dusk Blue #26538D ΔE 0.045
- Deep Sea Blue #015482 ΔE 0.045
- Dark Slate Blue #483D8B ΔE 0.060
- Marine Blue #01386A ΔE 0.061
- Blueberry #464196 ΔE 0.062
Use #1B4584 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.