Why do Marlboros have red tips?

From Allen Abel And Madeleine Czigler’s “Tangerine trees and marmalade skies” (National Post: 24 June 2008):

… it was [marketing sage & Chicago scientist Louis Cheskin] who turned Marlboro cigarettes from a woman’s brand — originally red-tipped to hide lipstick smears — into the cowboy-themed cancer sticks of universal renown.