Cultural variability. I don't go to many funerals. But I've done burials at sea, both casket and ashes, and I've done a "paddle out" for a surfer, where some 75 to 100 surfers paddled out on their boards, formed a huge circle, held hands, a Royal Hawaiian sang a sacred chant and the ashes were spread, while flowers were tossed into the circle.
When I attend a funeral in my home town, I wear a black suit, a blue tie, and stand next to the Constable.
That's the only time I wear a black suit anymore.