The video conferencing suite shown has a large conference table centered in the room.

Yellow-colored zones (any light fixture within the yellow zones directly above the seating area).

In video conferencing, balanced and well-placed lighting is crucial for achieving good facial visibility and reducing harsh shadows. Overhead lights can cast shadows on participants' faces, particularly under the eyes and nose, which can detract from a professional appearance on camera. By dimming lights directly above (in this case, the yellow zones), you reduce the intensity of the light falling straight down onto faces, softening shadows and creating more even lighting.

Dimming lights in the green or blue zones would be less effective, as they are positioned at the perimeter of the room and provide indirect lighting that does not directly influence facial shadows over the conference table.

CTS References: AVIXA CTS Exam Guide, Chapter on Lighting Considerations for Video Conferencing; CTS Handbook, Section on Proper Illumination Techniques for AV Environments.