Some lists and tables gray out their selection when they lose keyboard focus.
In the presence of multiple lists/tables, this helps communicate to the user which selection is active.
Is there an easy way to do this with NatTable?
The best I've come up with so far is to flip between different attributes for DisplayMode.SELECT as focus comes and goes -- but I'm not sure I can do that after NatTable.configure() has been called.
Yes you can change configuration attributes dynamically after NatTable#configure() has been called. That is a common approach for dynamic changes. Another approach would be to configure a selection style for a special label and apply that label only in case the table is active. This approach can be seen in this example.