Adjust Tilt. Try different color multipliers. I think color multiplier 91 or 25 is the most umbrella-like
Fibonacci didn't design an umbrella. I designed the umbrella based on based on golden angles (137.5°), creating "Fibonacci" spirals. Such spirals show up on pine cones, pineapples, and many flowers, but never before umbrellas. I've done too many golden angle based projects, but couldn't resist doing an umbrella.
