​

function setup() {

  createCanvas(500, 500);

  w = 25

  colorMode(HSB, 360, 100, 100);

}

​

function draw() {

  background(220);

  stroke(255)

  strokeWeight(.1)

​

  for (let x = 0; x < width; x += w) {

    if (mouseX > x && mouseX < x + w) {

      fill(map(x, 0, width, 0, 360), 100, 100)

​

    } else {

      fill(0, 0, 0)

    }

​

    rect(x, 0, w, height)

​

  }

​

​

​

​

​

}