.pimcore_icon_newsletter {
    background: url(/bundles/pimcoreadmin/img/flat-color-icons/feedback.svg) center center no-repeat !important;
}

.pimcore_icon_newsletterActive {
    background: url(/bundles/pimcoreadmin/img/flat-color-icons/invite.svg) center center no-repeat !important;
}

.pimcore_icon_newsletterConfirmed {
    background: url(/bundles/pimcoreadmin/img/flat-color-icons/feedback.svg) center center no-repeat !important;
}