Actually, Team Canada's jersey design changes every four years (atleast that's how it has been for approximately a decade). Think about it, each time Canada has been represented at the Winter Olympics from Lillehammer, Norway-to-Nagano, Japan-to-Salt Lake City, United States-to-Turin, Italy, the jersey designs have changed ever so slightly.
As for Canada switching to the black helmets, it began at the Salt Lake City Winter Olympic Games with the Men's team. They began to where those colour helmets, then they wore them at the World Cup, then the World Juniors and Women's team switched to the black helmets from the red ones. In regard to the World Juniors, I think the switch was made between the selection camp (red) and the first exhibition game (black). I don't think the helmet colour is a real problem, I mean Canada has been represented with white, red, and black helmets. It looks okay I guess, but that should not matter as long as they bring home Gold, right?