ATC calling out regional airlines in traffic advisories: phonetic or "aircraft paint" airline used? When ATC points out traffic that is a regional airline (e.g. Compass, Envoy, SkyWest, etc.), do they use the phonetic callsign of the airline, or do they use the callsign of the airline that they are operating as (how the plane is painted)?

The plane that a regional airline flies might be painted differently, depending on which airline they are flying for.

My thinking:

1) Pros of using the "aircraft paint": aircraft who are flying in VMC can spot each other more easily.

2) Pros of using the phonetic callsign: aircraft are on the same frequency in the same phase of flight, so they are more situationally aware if you use their phonetic callsign because they have probably already heard it in another transmission.
The call-sign is not used – it's as useful as saying the tail number if it's a GA plane ;)

The information given to the pilot is in FAA JO 7110.65 – section 2-1-21. TRAFFIC ADVISORIES.


Azimuth (o'clock position), or cardinal position (e.g., northeast) if moving rapidly
Distance
Direction and/or relative motion (e.g., southwest bound, converging)
If known, type and altitude.


Example:

ATC: [You], traffic, 12 o'clock, 10 miles, opposite direction, Boeing 737, one thousand above.



A comment by @user71659 remarked that Cockpit Display of Traffic Information (CDTI) can be used to follow traffic, and hence a call-sign/tail number would be given. This notice was cancelled in May of 2016 and was only to authorized users.