Cabbage Salad and Cole Slaw were definitely 50s salads too ... but probably you don't like them either.
No reason you have to put the carrot in with the pineapple for a jellied salad.
Pineapple with lime jello, is a nice combo.
Another popular at the time, more so with the adults than the kids at a sock hop was Tomato Aspic.
However, we get the message, that you don't do these salads,
therefore, maybe it would be better to tell the organizers
and ask to be switched to a different food item.