I'm painting the square archways in my house and I am not sure if I paint the upper part of the square arch white to match the ceiling or the same color as the room

I did mine the same colour as the room.

Tick

How are the archways finished? Are they finished with trim casing on each side?

If they are finished with s/r and no trim then normally paint them wall color.

If finished with wood frame and casing, normally paint the color of other trim in room.

The way u paint them is indivisible preference and want u will like.

If u paint same as walls, they will blend in and disappear.

If u paint them same as trim they will stand out more and be more visible.

It depends on the look u want.

Good luck

Chuck