My informant doesn’t remember having ever seen a red pen in her house. When she was in elementary school, she found out why. She’d written her name on a homework assignment in red colored pencil, and her mom made her erase it and write over it in black. Her mom explained that in ancient China, the names of people who were condemned to be executed were written in red ink, so writing your name in red is bad luck.
Though my informant doesn’t believe that signing her name in red will bring her bad luck, she never does it because “there’s no particular reason to sign in red when I could just as easily sign in any other color that isn’t associated with bad luck.”
I found this superstition interesting, since Chinese signature chops are usually stamped in red ink. Also, the Chinese consider red to be a lucky color. Both of these facts seem to contradict this particular superstition.