background images for overlay code example

Example 1: background image overlay

html {
  background:url(http://lorempixel.com/800/600/nature/2);
  background-size:cover;
  box-shadow:inset 0 0 0 2000px rgba(255, 0, 150, 0.3);
}

Example 2: css background overlay

.image:before{
    content: "";
        background: rgba(0,0,0,.6);
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 24px;
}

Example 3: make background overlay css

<div id="element-with-background-image">
   <div id="color-overlay"></div>
   ...
</div>