So what's to stop the Trumps from painting the White House gold? Protocol and custom provide checks and balances, but you know how much regard Trump has for both. "It is a matter of tradition rather than law," said the WWHA, when asked if the White House exterior color could be changed. "As a National Heritage Site/National Historic Landmark in the care of the National Park Service, there would be a significant process that would need to be followed to make any significant changes."