#1B559D
Closest named color: Dusk Blue (#26538D). oklch(45.3% 0.131 256.1), rgb(27, 85, 157).
Aa
White text reads best on this color (7.41:1).
About this color
#1B559D is a medium-dark, moderately saturated blue. In OKLCH its lightness is 45%, its chroma 0.131 and its hue 256°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk Blue (#26538D), ΔE 0.026 away. White text reads best on it, at 7.41:1.
| Hue family | Blues |
| Lightness | medium-dark (45%) |
| Chroma | moderately saturated (0.131) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 2.83:1 |
| White text | 7.41:1 |
Values
| HEX | #1B559D |
| RGB | rgb(27, 85, 157) |
| HSL | hsl(213, 71%, 36%) |
| OKLCH | oklch(45.3% 0.131 256.1) |
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 #1B559D | 7.41:1 | AAA | Lc -90.2 | Preferred for body text |
| Black text on #1B559D | 2.83:1 | Fails | Lc 18.7 | Dividers and decoration only |
| #1B559D text on white | 7.41:1 | AAA | Lc 85.3 | Fine for body text |
| #1B559D text on black | 2.83:1 | Fails | Lc -16.7 | Dividers and decoration only |
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 800.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E0EBF9
oklch(93.6% 0.022 254.4)
-
Step 200
200
#C7DBF6
oklch(88.5% 0.043 255.9)
-
Step 300
300
#A0C3F2
oklch(80.8% 0.077 255.9)
-
Step 400
400
#6CA3EC
oklch(70.8% 0.122 255.9)
-
Step 500
500
#4289E6
oklch(63% 0.157 256.2)
-
Step 600
600
#1F71D4
oklch(55.6% 0.17 256.1)
-
Step 700
700
#105EB8
oklch(49.1% 0.159 256.2)
-
Step 800
800 (this color)
#1B559D
oklch(45.3% 0.131 256.1)
-
Step 900
900
#174176
oklch(37.7% 0.102 256)
-
Step 950
950
#0F2645
oklch(26.9% 0.065 256.6)
#1B559D 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) | #2F5CA0 | 0.028 |
| Deuteranopia (no green cones) | #10509C | 0.016 |
| Tritanopia (no blue cones) | #006671 | 0.099 |
| Achromatopsia (no color) | #555555 | 0.131 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B559D
#1B559D
oklch(45.3% 0.131 256.1)
- #744D00
#744D00
oklch(45.2% 0.095 75.5)
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 #1B559D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk Blue #26538D ΔE 0.026
- Denim Blue #3B5B92 ΔE 0.041
- Cobalt #1E488F ΔE 0.041
- Light Navy Blue #2E5A88 ΔE 0.043
- Light Navy #155084 ΔE 0.043
- Deep Sea Blue #015482 ΔE 0.047
- Peacock Blue #016795 ΔE 0.056
- Dusky Blue #475F94 ΔE 0.058
Use #1B559D 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.