.wpcf7-form .wpcf7-response-output.wpcf7-validation-errors {
    color: #D8000C;
    background-color: #FFBABA;
    border: 0;
    padding: 10px;
}
.wpcf7-form .wpcf7-response-output.wpcf7-mail-sent-ok {
    color: #4F8A10;
    background-color: #DFF2BF;
    border: 0;
    padding: 10px;
}
div.wpcf7-mail-sent-ok:before,div.wpcf7-validation-errors:before {
    font: 26px/30px FontAwesome;
    margin-right: 16px;
    vertical-align: middle;
}
div.wpcf7-mail-sent-ok:before {
    content:'\f00c';
}
div.wpcf7-validation-errors:before {
    content:'\f057';
}