It seems there was a period in southern California (or was it all of California?) when traffic light poles were painted yellow. So...
Colorado Boulevard looking east from Los Robles Avenue, Pasadena, circa early to mid-1960s.
flickr.com
The traffic lights are attached to the lamp posts, so what they did was paint the lower part yellow. I didn't know they did that. Looks funny to me; kind of tacky.
Here's another example of that on West Main Street in Alhambra, 1956:
reddit.com TheWayWeWere
Alhambra, 1950s.
flickr.com timetravelnow