let angle = 0.0;
let r = 200;
function setup(){
createCanvas(600, 600);
background(220);
}
function draw(){
stroke(255-angle);
stroke(random(255),150,250)
let x = width/2 + cos(angle) * (r-angle);
let y = height/2 + sin(angle) * (r-angle);
line(width/2, height/2, x, y);
angle += 0.01;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.1.9/p5.min.js"></script>