.fa-star::before {
background: url(画像URL);
background-repeat: no-repeat;
background-size: 100%;
filter: grayscale(100%) brightness(200%) opacity(50%);
content: "\2003" !important;
}
.active > .fa-star::before, .notification__favourite-icon-wrapper > .fa-star::before {
filter: grayscale(0%) brightness(100%) opacity(100%);
}
.column-link > .fa-star::before, .column-header > button > .fa-star::before {
filter: grayscale(100%) brightness(150%) opacity(100%);
}