createCanvas(400, 400);

}

​

function draw() {

  background(0);

  noStroke();

 for(var i = 0; i<10; i++){

    if(mouseX > (width/10*i) && mouseX < (width/10 * (i+1)) ){

        fill(255,100,25*i);  

        rect(width/10*i,0,width/10,height);   

  }

}}

​