Well, I'm not an expert on archival permanence but over the years I have noticed a thing or two. Some years ago I was asked to copy a family photo dating back to around 1917: fibre based and still looking good.
Forty-year-old colour pics show serious fading and the negs are totally without any image.
According to Kodak their famous Kodachrome will last at least fifty years.
For me that's enough to know that B&W rules supreme.