As I delve into my ever-growing library, a few things strike me as odd, eccentric, probably apocryphal, but fascinating nonetheless.

One is the theory that hair color influences women’s perfume choices and that by using these data, we can figure out which fragrance families exert the greatest appeal. Reading this, I assumed it had to do with our own biochemistry and the correspondence between how we smell and our hair; I have, indeed, seen discussions of hair color and body odor.

However, my whole theory falls apart when one author—Paul Jellinek—states that natural hair color is irrelevant when it has been dyed. It is the color of the dyed hair, the final appearance, that’s important.

Another theory: perhaps there is a relationship between hair color and a usually unconscious synesthesia reaction in which color and odor are associated. I’ll have to ask Kate, my assistant who experiences this phenomenon, what she thinks.

Mr Jellinek discusses where on the diagram, shown below, the hair color affinities occur. Starting with blondes (who apparently have the least odor; Kate is consistent with this), perfumes along the line between anti-erogenic and stimulating, which is to say “refreshing,” are best. Less suitable for blonds are sultry (jasmine) or purely narcotic (rose) perfumes.

Exalting perfumes, which exist on the line between stimulating and erogenic, are best for redheads, while calming perfumes (between narcotic and anti-erogenic) are the worst things a redhead could wear.

Our author distinguishes between brunettes, who have legitimately brown hair, and “brown-haired” women—the large majority—whose hair is a combination of black and blond.

Brunettes should wear sultry perfumes—along the line between erogenic and narcotic. Fresh perfumes, between anti-erogenic and stimulating, are the worst. “Brown-haired women,” because their hair is of two colors, can wear much that blondes and brunettes can wear.