File | Settings | Appearance and Behavior for Windows and Linux

IntelliJ IDEA | Preferences | Appearance and Behavior for OS X ⌘, or ⌘,⌘, or ⌘,⌘, or ⌘,⌥ F7, ⌥F7 or ⌥F7^ ⌥ S, ⌃⌥S or ⌃⌥S

settings

When you select the Appearance and Behavior category in the left-hand pane, its main subcategories are listed in the right-hand part of the dialog.