background change - OpenProcessing

mySketch
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let cx, cy;
let cw = 80;
let on = true;
let color1, color2, color3;
let state = 0;
let bg;
function setup() {
  createCanvas(windowWidth, windowHeight);
  cx= width/2;
  cy=height/2;
  color1= color( 255, 0,134);
  color2= color( 200, 0,0);
  color3= color( 200, 242,34);
  bg=color1;
  
}
​
function draw() {
  background(bg);
  
  if(state == 0){
    bg=color1;
  }else if (state == 1){
    bg=color2;
  }else {
    bg=color3;
  }
  fill(255);
ellipse(cx,cy,cw,cw);
  
}
​
function mousePressed() {
  let d = dist(cx, cy, mouseX, mouseY);
  if (d < cw/2) {
    //console.log("click"); 
    if(state == 0){
      state = 1;
    } else if(state==1){
      state = 2;
    }else if (state==2){
    state = 3
    }else{
      state=0
    }
  }
}