As you can see it edits the symbol for the feature I had selected. I want to do this to ALL of the unique values of this feature class. But when I go to the 'More' -> 'Symbols' -> 'Format all symbols' for example, the option to add a layer effect is not there. Same for when I select more than one value and a time and do 'More'-> 'format symbol(s), the option to add a layer effect is not there.
Is it possible that the only solution to this is to edit each value's symbol one by one? I have hundreds in this feature class I need to edit.