<style>
  body {
    display: flex;
    align-items: center;
    justify-content: center;

    background: repeating-linear-gradient(
        -45deg,
        transparent 0,
        transparent 25%,
        dodgerblue 0,
        dodgerblue 50%
      ),
      repeating-linear-gradient(
        45deg,
        transparent 0,
        transparent 25%,
        tomato 0,
        tomato 50%
      ),
      white;

    background-blend-mode: multiply;
    background-size: 80px 80px;
  }
</style>