Function to_hex 

pub fn to_hex(c: AlphaColor<Srgb>) -> String

#RRGGBB (upper-case, alpha dropped) for a colour.

use tilo_ui::color::to_hex;
use tilo_ui::vello::peniko::Color;
assert_eq!(to_hex(Color::from_rgb8(0x3B, 0x82, 0xF6)), "#3B82F6");