Thanks, tried that and ended up with the same almost unreadable light blue background for the header. The Custom CSS textarea is now empty except for the
.wp-table-reloaded th, .wp-table-reloaded .sorting {
background-color: #3300ff;
}
.wp-table-reloaded .sorting_asc, .wp-table-reloaded .sorting_desc {
background-color: #000066;
}
