Add this to your Local CSS.

/*This code removes reverse background from plone forms labels*/

.label, .badge {
    background-color: #FFFFFF;
                color: #000000;
    font-size: 10.998px;
    font-weight: normal;
    line-height: 14px;
    text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.25);
    vertical-align: baseline;
    white-space: nowrap;
}

It's Not prefect, but it is an improvement.