Fibonacci Blue
#112358
Bright cobalt-blue undertone for confident contrast
About Fibonacci Blue
On my monitor, Fibonacci Blue looks like a purple that's been tuned by a cool breeze: crisp, mid-deep, and clearly blue-leaning without turning into a royal navy. Compared to Black Sea Night, it doesn't sink into near-black. Compared to Dark Sapphire, it's brighter and more saturated, with a steadier blue bias. And compared to Deep Sea Nightmare, it has more presence and lift, so it reads as a deliberate color, not just ink.
I reach for it in dashboards and finance apps when you want a sharper secondary accent: chart highlights, data focus states, tag outlines, and hover treatments that need to stay legible against dark gray. In healthcare software, it also works well for form feedback and action emphasis where you want confidence without the heavier, darker "night ink" feeling.
Pair it with cooler greys and clean, neutral surfaces. If you push it next to warm tones, the blue edge softens and the purple starts to look muddy, fast.
Code snippets
Copy this color into your project.
Contrast checker
WCAG 2.1 contrast ratios. AA requires 4.5:1 for normal text, 3:1 for large. AAA requires 7:1 / 4.5:1.
On White #ffffff
On Gray 100 #f5f5f5
On Gray 900 #18181b
On Black #000000
Variations
Shades
Darker variations, created by mixing toward black.
Tints
Lighter variations, created by mixing toward white.
Tones
Muted variations, created by reducing saturation.
Hues
Hue rotations around the color wheel.
Temperatures
Warm and cool shifts of this color.
Color harmonies
Suggested palettes
Palettes built around this color.
Community palettes
Published palettes that include this color.
