Character Settings is different than the built-in game settings. Character Settings are optional features that are provided by our server and you are able to change these options on each of your characters for different needs.
You can access the Character Settings a couple ways:
right click character, choose Character Settings option from the dropdown list
click the Silver Gear icon at the bottom-center of the minimap (not to be confused with the smaller Gold Gear icon that opens the game menu), you can also type /settings in chat to open it