adding overlay usign background image code example

Example 1: how to have a background image with a color overlay

/* Working method */
.tinted-image {
  background: 
    /* top, transparent red, faked with gradient */ 
    linear-gradient(
      rgba(255, 0, 0, 0.45), 
      rgba(255, 0, 0, 0.45)
    ),
    /* bottom, image */
    url(image.jpg);
}

Example 2: how to add a background overlay in css

.header {
  background: rgba(0, 0, 0, 0.5); /* Black color with 50% alpha/opacity */
}