how to add a black shade on background images css code example

Example: tint image with background color css

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