(lightness-from-rgb 
.(vconcat 
..(vabs 
...(v- 
....(vround 
.....(vmod vsnoise [-0.375 0.5085])) 
....(square grain))) 
..(t 
...(vround 
....(square [1.0545 -0.8965 -1.1921 -2.2073]))) 
..(v+ 
...(y 
....(hue-from-rgb 
.....(blue-from-hsl 
......(sigmoid 
.......(adjust-hue 
........(blue-from-hsl pos) [0.6155 2.5684 -2.3772 -2.1781]))))) 
...(polar 
....(rgb-from-hsl 
.....(radius vnoise))))))