Choose the color according to your preference. However, it is best to use light-colored paint for the ceiling, preferably white. The dark ceiling will make the room dark and give people a feeling of depression.

If you really want to paint the ceiling light gray, you should first look at what color the surrounding walls are painted. Many colors don't go well with gray. If it is not well matched, it will look awkward as a whole.

Usually rooms are handled from top to bottom, from shallow to deep.