We are allowed to wear black and dark blue jeans here. They don't want to spend the money to order anymore of the black work pants here, but the official excuse was that they were no longer available.
When I started, it was mandatory to wear black pants but no jeans. A few years ago, we were allowed to wear jeans(I see mostly blue, black and sometimes white).
It might be a regional decision so the person to ask would be your store management.
Just checked Employee Handbook:
"All employees are to wear clean black pants or jeans as long as they are tasteful. No frayed, faded or ragged jeans are permitted. Black pants and black jeans must be kept pulled up. No "low riders" will be permitted nor will visible undergarments. Blue jeans, sweat pants, stretch pants, capris, skirts, or culottes are not permitted."
I think the only thing that was off limits were leggings at the store I was at. I was able to get away with pants that could've passed as sweats. They were gray.
I figured, working in the deli, jeans aren't as comfortable to move around in.
Just look around the store and see what the other employees are wearing to find out what's acceptable. Some stores are more lax than others. At mine, many people wore regular old blue jeans.