let yInt= 10;

function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  background(0);

  for (x=0; x<width; x+=xInt){

    stroke(x/2, 100, 0)

        strokeWeight(5)

    line(x,0, x, height);

  }

  for (y=0; y<width; y+=yInt){

    stroke(0, 100, y/2)

    strokeWeight(5)

    line(0,y, width, y);

  }

  xInt = map(mouseX, 0, width, 10, 100, true);

  yInt = map(mouseY, 0, height, 10, 100, true);

}

​