I have a data table that can sort/filter columns, but there are certain columns that can't be sorted or filtered. I'm trying to find the best way to indicate to users which columns they are with the least amount of steps possible. Ideally, I would like them to figure it out without having to hover over the column headers.
Here are some of my ideas:
(Note: Sortable/filterable columns have an underlined column header on rollover)