Should toggle buttons show current state?
Usability tip: If the toggle is an action (Play/Pause) the label / title should show what will happen. If the toggle is an option (On/Off) then it should show the current state.
What are tertiary buttons?
Tertiary buttons are an optional third style for buttons, these are usually used for actions such as 'cancel' or 'close' actions. They may technically be a button but often they have no background or outline until a user hovers over them, so they simply appear as the label.