I would go with the navy or charcoal, especially dark charcoal. I’ve worn a navy suit with a black tie to a wake before. Maybe it’s a newer thing, but the immediate family of the recently passed didn’t wear black – on purpose. For them, they didn’t need to feel even more grim is what one of them told me. So, I think navy or dark charcoal would work for funerals. Traditional? No, but it still can convey a respectful tone.
Wearing black is such a powerful statement of formality and (sometimes) somberness, yet can also be interpreted as fashionable. I don’t think a black suit is very “conservative” in comparison to navy or dark charcoal. It’s a strong statement.