in the webassist/forms/fd_swisswebfactory_bravehearts/Datepicker/css/jquery-custom.css file, change:
.ui-state-error, .ui-widget-content .ui-state-error {
border: 1px solid #CD0A0A;
background: #FEF1EC url(images/ui-bg_inset-soft_95_fef1ec_1x100.png) 50% bottom repeat-x;
color: #CD0A0A;
}
to:
.ui-state-error, .ui-widget-content .ui-state-error {
border: 1px solid #CD0A0A;
/*background: #FEF1EC url(images/ui-bg_inset-soft_95_fef1ec_1x100.png) 50% bottom repeat-x;*/
color: #CD0A0A;
}