#1B4289
Closest named color: Cobalt (#1E488F). oklch(39.5% 0.127 261.2), rgb(27, 66, 137).
Aa
White text reads best on this color (9.60:1).
About this color
#1B4289 is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.127 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.019 away. White text reads best on it, at 9.60:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.127) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.18:1 |
| White text | 9.60:1 |
Values
| HEX | #1B4289 |
| RGB | rgb(27, 66, 137) |
| HSL | hsl(219, 67%, 32%) |
| OKLCH | oklch(39.5% 0.127 261.2) |
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 #1B4289 | 9.60:1 | AAA | Lc -96.1 | Preferred for body text |
| Black text on #1B4289 | 2.18:1 | Fails | Lc 12.1 | Not readable |
| #1B4289 text on white | 9.60:1 | AAA | Lc 91.8 | Preferred for body text |
| #1B4289 text on black | 2.18:1 | Fails | Lc -10.6 | 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
#E0EBFD
oklch(93.7% 0.027 260.3)
-
Step 200
200
#C6DAFD
oklch(88.5% 0.053 261.7)
-
Step 300
300
#9EC1FF
oklch(80.8% 0.096 261.6)
-
Step 400
400
#699FFF
oklch(70.8% 0.152 261.1)
-
Step 500
500
#4083FD
oklch(63.2% 0.195 261.2)
-
Step 600
600
#1F68EC
oklch(55.5% 0.212 261.3)
-
Step 700
700
#1256CD
oklch(49.1% 0.196 261.1)
-
Step 800
800
#1247A6
oklch(42.7% 0.163 261.2)
-
Step 900
900 (this color)
#1B4289
oklch(39.5% 0.127 261.2)
-
Step 950
950
#0E244D
oklch(26.9% 0.081 261.5)
#1B4289 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) | #164A8C | 0.022 |
| Deuteranopia (no green cones) | #004088 | 0.017 |
| Tritanopia (no blue cones) | #00535F | 0.098 |
| Achromatopsia (no color) | #454545 | 0.127 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B4289
#1B4289
oklch(39.5% 0.127 261.2)
- #5C4100
#5C4100
oklch(39.5% 0.081 81.8)
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 #1B4289, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.019
- Twilight Blue #0A437A ΔE 0.029
- Light Navy #155084 ΔE 0.042
- Dusk Blue #26538D ΔE 0.052
- Deep Sea Blue #015482 ΔE 0.055
- Dark Slate Blue #483D8B ΔE 0.058
- Blueberry #464196 ΔE 0.058
- Sapphire #2138AB ΔE 0.061
Use #1B4289 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.