body {
    background-image:
      linear-gradient(45deg, orangered 25%, transparent 25%),
      linear-gradient(45deg, transparent 75%, palegoldenrod 75%),
      linear-gradient(45deg, transparent 75%, palegoldenrod 75%),
      linear-gradient(45deg, palegoldenrod 25%, forestgreen 25%);    

    background-size:100px 100px;       

    background-position:0 0, 0 0, -50px -50px, 50px 50px;
}