One of the ways this can be obtained is by stacking gradients. You will have one gradient representing the colored-horizontal lines, then adding in white vertical lines as a second gradient. (It can be white, or what ever color your background is).
.solid-lines {
padding-left:5px;
background-image:linear-gradient(to right, #fff 5px, transparent 1px), linear-gradient(#ccc 1px, transparent 1px);
background-size: 20px 30px;
}
The added padding is for the offset of the first line. The background size (20px) represents the space in-between each white vertical line, and '5px' is the size of that line. Tweak these numbers to get the dashed look you want.
http://jsbin.com/weyozutawiva/1/