In George Orwell's Keep the Aspidistra Flying, the protagonist gets a job at a "red lead firm". From context, it seems to mean a well-established, maybe stuffy, firm. I wonder if anyone has a more specific description. Here's the passage:
And then Gordon left school, and fat interfering Uncle Walter, who had business connexions in a small way, came forward and said that a friend of a friend of his could get Gordon ever such a 'good' job in the accounts department of a red lead firm.
Unfortunately, all my searches just turn up stuff about a red oxide of lead.