#adminmenu #toplevel_page_dmarcian .wp-menu-image {
    background: url(../icons/black-and-white.png) no-repeat center;
    background-size: 18px 18px;
}

#adminmenu #toplevel_page_dmarcian .wp-menu-image.green-logo {
    background-image: url(../icons/green.png);
}

#adminmenu #toplevel_page_dmarcian .wp-menu-image.red-logo {
    background-image: url(../icons/red.png);
}