Jeff was the black guy? I watched him the other day and noticed he really looked like he was working—filing receipts, posting schedules, and things like that.
Both Louie and Latka were usually on the periphery and interacted with the principal five to advance the plot, or when the story-of-the-week focused on them
I remember reading an article years ago saying, ‘watch for the woman in the green dress who is an extra. She is in a lot of episodes of MTM in the background, walking down the street, riding up an escalator, a customer in the background in a restaurant.’ Once you see her, you spot her all the time… There’s something about green that catches the eye. When there were showings of ‘colorized movies’, it was easy to tell if it was colorized because the green color was so garish and obvious.
Remember the girl with the glasses who gets off the crowded elevator while Mary catches her breath in the background? I would swear she’s a Norwegian exchange student who was at my high school in the early '70s.
Yes. Played by J. Alan Thomas
Sounds like Gunther from Friends. He was not supposed to be anything more than a non-speaking extra but when people began to notice him they gave him lines.
Frank Adamo was on at least 51 episodes of The Dick Van Dyke Show. He played different characters almost every time. He must have been a friend of either Van Dyke or Carl Reiner as he then appeared on at least 5 episodes on The New Dick Van Dyke Show playing different characters.
He even had a tiny role in Fitzwilly & Bye Bye Birdie. So probably friends with Van Dyke.
If you binge The Dick Van Dyke Show you can’t help but notice him.
“She plays with drips, he paints on mustaches!” 
IMDB says he was Van Dyke’s personal assistant, not an actor.
He was Gunthering before that was a thing.
I agree. I think the only background player who ever had any lines was John Amos, who played Gordy, the weatherman; and his speaking roles were infrequent, though he was often seen in the background.
I did appreciate the Lou Grant show, where background players did just as they did on the MTM show, (i.e. looked like they were working, such as typing, making and taking phone calls, etc.), but so did the lead players. I’ve been in a newspaper’s newsroom once or twice, and Lou Grant got it correctly in the background.