You can download the pattern or use the CSS3 code below (you can copy the text).
body {
/* CSS3 pattern provided by JonesPatterns.com */
background-image: linear-gradient(90deg,#880000 50%,transparent 50%);
background-image: -webkit-linear-gradient(0deg,#880000 50%,transparent 50%);
background-image: -o-linear-gradient(90deg,#880000 50%,transparent 50%);
background-color:red;
background-size: 50px 50px;
}