CSS

repeating-linear-gradient generator

body {
  background-image: repeating-linear-gradient(-45deg,
      transparent,
      transparent 20px,
      black 20px,
      black 40px);
   width: 3px;
}

repeating-linear-gradient generator

body{
	background: repeating-linear-gradient(
		to right bottom,		
		#C80A0A ,
		#C80A0A 5%,
		#880D0D 5%,
		#880D0D 10%
		);
}
/*
body{
	background: repeating-linear-gradient(
		to right bottom,					select the direction (could be also in deg)
		#C80A0A ,							color + start position
		#C80A0A 5%,							color + start position
		#880D0D 5%,							color ...
		#880D0D 10%							color ...
		);
}
*/