Most of the ones I have seen 1947-53 are rusty and/or brown.
See attached pictures.

The 54 and 55 1st radios are different in construction. Maybe a silver color on the chassis.
Denny's Website:
https://www.pbase.com/dennygraham/986771_radio_truck&page=all
Attachments
Radio 01.jpg (78.37 KB, 95 downloads)
Radio 02.jpg (71.08 KB, 95 downloads)


"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."