All the Doors Were Red

But it was not the plains Dany saw then. It was King’s Landing and the great Red Keep that Aegon the Conqueror had built. It was Dragonstone where she had been born. In her mind’s eye they burned with a thousand lights, a fire blazing in every window. In her mind’s eye, all the doors were red. 

A Game of Thrones, Dany III.