You should use CSS for that, but the CSS classes for the header cells are broken. I’m posting and update to fix it (1.6.35).
The table, header, and table cell elements have classes based on the item type and nickname:
* The table tag class is “fm-data”
* Header (th) class is “fm-item-header-(nickname)” where (nickname) is replaced with the item nickname
* Cells (td) class is “fm-item-cell-(type)”, where (type) is replaced with the type name for the item type. This will be ‘text’, ‘textarea’, ‘custom_list’ (which applies to all the list types), ‘checkbox’, ‘file’, etc., for the full list look at the top of types.php.
