Do floor molding and door trim need to match?

I'm thinking about replacing my floor molding and have heard that the floor molding and door trim must match in order to be "proper". Is this true?

According to Miss Manners, yes, to entertain with mis-matched trim you would be dropped from the invitation list for the upcoming social season. You'll find yourself sitting home alone on New Year's Eve.
Just use a little common sense. If one is painted, both probably should be painted If one is rather gaudy, the other may look out of place if a plain clamshell. Your house, your rules, but you probably want something that complements the style of the house. Installing it really isn't that difficult. A good miter saw is necessary to make the various cuts. Like a good 45 degree angle. I found that using a cheap plastic mitre box and a hand saw was a real pain. By using a good power saw, the cuts will look better and you will keep your sanity.