A red door has several meanings. In China, a red door is the same as a welcome mat. It also symbolizes good luck, so painting a door red in China would be to welcome people to your home and also encourage good luck to enter. In old colonial America, a red door was symbolic of a safe haven. Travelers used to look for red doors on houses as signs of welcome and safety. In Catholicism, a red door symbolizes the blood of Christ, which meant that once you passed the door, you were on holy ground. In Scotland, people paint their doors red to indicate that they have paid off a mortgage. In essence, a red door means divine protection, good luck and money, so no matter what you need, go behind the re...