The colors of the AQM-34 Firebees are rather unclear. The following color and schemes were identified:
Many photos in 'Lightning Bugs and other reconnaissance drones' suggest an overall black scheme. However, many were orange-red in reality. Apparently this color shows as black in black and white photos. Just as an example, take the first Model 147A models, on page 28: it looks black but was orange. It isn't likely that the USAF flew orange-red AQM-34's operationally, but many test birds were painted in this color.
There were black operational AQM-34s. Definitely confirmed to be black were the 147SRE aka AQM-34K night recce Firebees. 'Lightning Bugs' page 142 quotes "This visual night reference [reflective tape] was necessary as no detail whatever of an absolutely black bird can be seen against an absolutely black sky". The USAF Museum's AQM-34N and the Pima AQM-34Q appear to be the only remaining black examples.
Most of the low-level AQM-34L/Ms seem to have been painted light gray overall, probably FS x6492, either 26492 or 16492.
The Navy Model 147SKs had a three-tone grey scheme, with scallops. It is also seen on some Air Force AQM-34Ls.
Some of the camo pattern of an 147NP model can be seen on page 123 of 'Lightning Bugs'. Colors are not known.
Larry Engesath's photos from 1973 show a two-color grey scheme, with FS 36622 on the lower side and possibly US Navy gull gray on the top side
The long tailcone (housing two parachutes) appears to have been black on almost all Firebees. On later models, the forward part of the cone is sometimes in the camouflage color too. The 'radar blankets' (aka RAM) reported in the first chapters of 'Lightning Bugs' appear to be white.
Some snippets about markings:
On early Model 147s, the usual identification appears to have been the model number from the factory Model 147 designator (like 'B' for the Model 147B), followed by a sequence number, starting at 1
On later Model 147s, the usual identification appears to have been the suffix letter of USAF model designator (AQM-34L gives L for example), followed by a sequence number, starting at 1
Some had (parts of) their USAF serial numbers painted on. On some the last four digits were painted in various locations.
Tail codes: 'DM' for the Davis-Monthan based TAC units that operated AQM-34's. 'HI' is also known (AQM-34V), possibly used by 6514th Test Squadron while bases at Hill AFB.
No national markings or 'U.S. AIR FORCE' markings appear to have been carried. Exceptions are test birds flown over and around the USA.
A nickname was given after given after five completed operational missions.
Mission markings were generally started on the left side, but could overflow to the right side.
Stencils were very limited or absent.
A turbine warning stripe was usually applied to the nacelle.
'Lightning Bugs' page page 65 reports that in 1964, 147B's were flown with Taiwanese roundels.
The US Air Force published generic painting instructions for drones in various Technical Orders. They seems to apply more to BQM-34s target drones than AQM-34s reconnaissance RPVs.
USAF Tech Order 1-1-636 'Exterior finishes, insignia and markings applicable to USAF aircraft' from 1957, sections 3-41 to 3-44, specifies 'insignia red' for drones. In the (later) FS595 system, this is FS 11136. Screen shot courtesy of 'Sabrejet'
USAF Tech Order 1-1-4 'Exterior finishes, insignia and markings applicable to aircraft and missiles' from 1964, section 3-62, specifies 'fluorescent red-orange, Color No 633' for target drones. This color is part of the ANA166e color range that was used before FS595. Dave Klaus, in 'The IPMS color guide' page 115, states that Color No 633 is the equivalent of FS 28913, although this is not formaly identified in ANA166e or FS595
USAF Tech Order 1-1-4 'Exterior finishes, insignia and markings applicable to USAF aircraft' from 1978, section 4-17, specifies 'international orange, Color No 12197' for target drones.
USAF Tech Order 1-1-4 'Exterior finishes, insignia and markings applicable to USAF aircraft' from 1994, section 4-17, specifies FS 12197 for target drones. This TO is reproduced in Dana Bell's USAF colors and markings in the 1990's)
To cover Navy BQM-34 Firebee target drones too, here are some Navy painting instructions.
Navy manual MIL-STD 2161A 'Paint schemes and exterior markings for US Navy and Marine Corps aircraft' from 1993 states:
section 5.1.4 specifies FS 12197 (international orange) and FS 17925 (insignia white) for drones
section 5.1.5 specifies FS 28915 (fluorescent orange-yellow) for target aircraft
This makes it rather unclear what color a 'target drone' is to be painted in. The manual does not have a drawing with colors and markings for the BQM-34, but the one for the BQM-74C (figure C-50 on page 191) shows FS 12197 as the main color. There are many photos showing Navy BQM-34 in FS 28915 fluorescent orange-yellow.
Navy manual MIL-STD 2161C 'Paint schemes and exterior markings for US Navy and Marine Corps aircraft' from 2014 changed section 5.1.4: instead of FS 12197 it is now FS 22190. The colors are very close, with the latter maybe redder and brighter.
This Don Color page (archived by the Wayback Machine) about the '1959 USN Firebee paint scheme' reports ANA 633 Fluorecent Red Orange
Modeler/writer Colin Sponner writes in Scale Models International, December 1989 issue, that the Navy used Insignia Red (FS 11136) for drones from 1946 to 1959, and Fluorescent Yellow-Orange (FS 28915) after that
Testors/Italeri has FS 28913 in its Model Master II range (#2041). Humbrol has no match, and neither does Revell-Germany.