How to change revolution slider background color opacity

How to change revolution slider background color opacity

.rev_slider .slotholder:after { width: 100%; height: 100%; content: “”; position: absolute; left: 0; top: 0; pointer-events: none; background: rgba(255, 255, 255, 0.5); } Can do the same for section background image, just need to add a class to the container and put the .classname in place of .rev_slider .slotholder