Remove furniture from the room. Spread a tarp on the floor. Tape along the perimeter of the room where the wall meets the ceiling to protect the walls from paint.
Purchase two shades of the same color paint to match the two colors of the unpainted ceiling texture. Use a high-res photo reference to match the colors in the store.
Open and stir the darker paint shade. Pour 1/2 cup of the paint into the tray.
Fit the low nap roller onto the extension pole and dip the head into the paint.
Roll the head against the textured portion of the tray to distribute the paint evenly. Stop rolling when the paint makes a tacky sound.
Paint along the perimeter of the room and then move in towards the center of the room.
Use a smaller roller or paint brush to touch up the perimeter and corners where the large roller cannot reach.
Wait for the first coat to dry 6 to 12 hours. Apply a second coat.
Clean the paint tray and load it with the light shade. Switch to the no-nap roller head.
Load the roller with very little paint to prevent dripping.
Paint the perimeter then the center of the ceiling.
Wait for the paint to dry and then observe the effect. The plateaus should be lighter that the valleys, creating depth.
Use a small brush to fill in any areas with the lighter or darker shade as needed.