#1B579E
Closest named color: Dusk Blue (#26538D). oklch(45.9% 0.13 255.3), rgb(27, 87, 158).
Aa
White text reads best on this color (7.23:1).
About this color
#1B579E is a medium-dark, moderately saturated blue. In OKLCH its lightness is 46%, its chroma 0.130 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk Blue (#26538D), ΔE 0.028 away. White text reads best on it, at 7.23:1.
| Hue family | Blues |
| Lightness | medium-dark (46%) |
| Chroma | moderately saturated (0.130) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 2.90:1 |
| White text | 7.23:1 |
Values
| HEX | #1B579E |
| RGB | rgb(27, 87, 158) |
| HSL | hsl(213, 71%, 36%) |
| OKLCH | oklch(45.9% 0.13 255.3) |
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 #1B579E | 7.23:1 | AAA | Lc -89.6 | Fine for body text |
| Black text on #1B579E | 2.90:1 | Fails | Lc 19.4 | Dividers and decoration only |
| #1B579E text on white | 7.23:1 | AAA | Lc 84.7 | Fine for body text |
| #1B579E text on black | 2.90:1 | Fails | Lc -17.3 | 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
#C7DBF5
oklch(88.5% 0.042 255)
-
Step 300
300
#A0C3F2
oklch(80.8% 0.077 255.9)
-
Step 400
400
#6BA3EB
oklch(70.7% 0.122 255.2)
-
Step 500
500
#418AE5
oklch(63.1% 0.155 255.4)
-
Step 600
600
#1B72D3
oklch(55.7% 0.169 255.1)
-
Step 700
700
#0B5FB7
oklch(49.2% 0.157 255.2)
-
Step 800
800 (this color)
#1B579E
oklch(45.9% 0.13 255.3)
-
Step 900
900
#164176
oklch(37.6% 0.102 255.6)
-
Step 950
950
#0E2745
oklch(27.1% 0.064 254.6)
#1B579E 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) | #325DA1 | 0.028 |
| Deuteranopia (no green cones) | #16529D | 0.015 |
| Tritanopia (no blue cones) | #006873 | 0.098 |
| Achromatopsia (no color) | #575757 | 0.130 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B579E
#1B579E
oklch(45.9% 0.13 255.3)
- #764E00
#764E00
oklch(45.7% 0.096 75.1)
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 #1B579E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk Blue #26538D ΔE 0.028
- Denim Blue #3B5B92 ΔE 0.038
- Light Navy Blue #2E5A88 ΔE 0.041
- Light Navy #155084 ΔE 0.046
- Cobalt #1E488F ΔE 0.046
- Deep Sea Blue #015482 ΔE 0.049
- Peacock Blue #016795 ΔE 0.051
- Dusky Blue #475F94 ΔE 0.054
Use #1B579E 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.