Quote from Rose in The Pope's Ring
Rose: Well, if it's important to you, I'll support you. But why didn't you tell me about it earlier? Miles: Well, for the same reason that those formulas that dye hair do it gradually. I mean, it's the kind of thing you want people to notice, but not to be able to pinpoint. Rose: I didn't know you dyed your hair. Miles: Rose, my hair is gray. It's been gray since we met. Rose: Boy, that is gradual.