He was considered to be "as dead as a door nail"
In "A Christmas Carol" by Charles Dickens, Jacob Marley is dead as a door nail. He appears as a ghost to warn Scrooge about his fate if he does not change his ways.
Marley was as "dead as a door nail". Here is a quote from the book: "Old Marley was as dead as a door-nail. Mind! I don't mean to say that I know, of my own knowledge, what there is particularly dead about a door-nail. I might have been inclined, myself, to regard a coffin-nail as the deadest piece of ironmongery in the trade. But the wisdom of our ancestors is in the simile; and my unhallowed hands shall not disturb it, or the Country's done for. You will therefore permit me to repeat, emphatically, that Marley was as dead as a door-nail. "
There is more than one answer to this question because different areas seem to have adapted it to suit them. Answers are 1) Dead as a Dodo. 2) Dead as a Door nail. 3) Dead as Door knocker.
It's a very old metaphor for death - it was seen in print by 1350.
"When doors were built using only wood boards and hand forged nails, the nails were long enough to dead nail the (vertical) wooden panels and (horizontal) stretcher boards securely together, so they would not easily pull apart. This was done by pounding the protruding point of the nail over and down into the wood. A nail that was bent in this fashion (and thus not easily pulled out) was said to be dead. Thus the expression - dead as a doornail."
"I am as light as a feather, I am as happy as an angel, I am as merry as a schoolboy." "I could eat a horse, hoofs and all." "I could drink a river of brandy and never get drunk." "I was as merry as a cricket."
The nail itself is dead, but the follicle that produces it is still alive.
It starts with the narrator saying "Marley was dead: to begin with. There is no doubt whatever about that. The register of his burial was signed by the clergyman, the clerk, the undertaker, and the chief mourner. Scrooge signed it: and Scrooge's name was good upon 'Change, for anything he chose to put his hand to. Old Marley was as dead as a door-nail."
All of the nail is made up of dead cells.
The term "deadbolt" for a door lock comes from the idea that the bolt does not move on its own, hence "dead." On the other hand, the phrase "dead as a doornail" referring to being completely lifeless or devoid of activity comes from the historical practice of securing doors with large-headed nails that were hammered in and then "dead" as they couldn't be reused. The two terms are not directly related in origin.
Dark red should do it.