bright lights

bright and early

(Very) early in the morning.

bright line

A clear distinction in the context of a legal, moral, ethical, or analytical judgment.

bright side

A consoling aspect of a difficult situation.

bright spark

A person who is intelligent, clever or quick-witted.

bright young thing

One who is youthful, clever, eager, and high-spirited in manner and attractive in appearance.

lights-out

Something hopeless, over; unconsciousness.

look on the bright side

To examine a situation, usually unfavorable, from a positive perspective; to be cheerful or optimistic.

look on the bright side of it

To examine an aspect or facet of something in a positive view.