add color on image using css

header {
    height: 600px;
    width: 100vw;
    background: black;
    overflow: hidden;
    background: #C33764;  /* fallback colour. Make sure this is just one solid colour. */
    background: -webkit-linear-gradient(rgba(29, 38, 113, 0.8), rgba(195, 55, 100, 0.8)), url("https://bit.ly/2rlzaXi");
    background: linear-gradient(rgba(29, 38, 113, 0.8), rgba(195, 55, 100, 0.8)), url("https://bit.ly/2rlzaXi"); /* The least supported option. */
}

img {
   object-fit: cover;
}