Empty materials from Blender to Unity

Hello, I have got this Google Earth capture as a background to a building that will be in the middle. Because it's a capture, I don't have the textrues from the objects saved and I would need to know if there is a way to export the models with all the materials already appended to them, so they would appear textured even in Unity. (1st picture: the objects look in Blender, 2nd picture: how they look after exporting and putting in Unity)