Celery Jello Substitute

When I was a kid, celery jello existed (Yes, I am really old). I have a vague memory of a jello salad made with grated carrot, thin sliced radishes, and thin sliced celery. It was dressed with mayo. My child's memory is that I really liked it, but who knows how it really taste? I want to try making it but alas, celery jello is no more. I can get unflavored gelatin but how would I make it celery flavored? Is celery juice a thing? Thanks!