.banner-4 {
    background-image: url("../images/backgroundTest.jpg");
    background-size: 100vw;
    background-repeat: no-repeat;
    position: relative;
    z-index: 1;
    background-color: rgba(255,255,255,0.7);
    background-blend-mode: overlay; }

.slick-prev:before, .slick-next:before  {
    color: blue !important;
}