css background overlay

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

                                    #element-with-background-image {
   position: relative;
   background-image: url("//spin.atomicobject.com/wp-content/uploads/20170324102432/portfolio-tips-feature-image.jpg");
}
 
#color-overlay {
   position: absolute;
   top: 0;
   left: 0;
   width: 100%;
   height: 100%;
   background-color: black;
   opacity: 0.6;
}

                                    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);
}

                                    .testclass {
    background-image: url("../images/image.jpg"), linear-gradient(rgba(0,0,0,0.5),rgba(0,0,0,0.5));
    background-blend-mode: overlay;
}

                                      background: linear-gradient(#3204fdba, #9907facc), url(https://picsum.photos/1280/853/?random=1) no-repeat top center;