let colors = [];

​

function setup() {

  createCanvas(400, 400);

  var r = random(100, 255), g = random(100, 255), b = random(100, 255);

  colors[0] = color(r, g, b);

  for(var i = 1; i < arcs; i++){

    colors[i] = color(r-i*5, g-i*20, b-i*8);

  }

  frameRate(30);

}

​

function draw() {

  background(255);

  translate(width/2, height/2);

  noFill();

  strokeWeight(4);

  for (var i = 0; i < arcs; i++){

    push();

    rotate((millis()/(1000*i)));

    stroke(colors[i]);

    arc(0, 0, size - i*space, size - i*space + sin(frameCount/10)*100, i*QUARTER_PI + (frameCount/(10*i)), i*QUARTER_PI + PI + (frameCount/(10*i)), OPEN, 50);

    pop();

  }

}