Painting a plane requires up to 13 days of well-organized work. As I was in Tarom's backstage, I saw a broken plane in the hangar. He had come for the general technical review, but also for repainting. Tarom was to rent that aircraft to an airline and it had to be painted in the colors and logo of that company.
As can be seen in the image above, the technical review plan was well structured on days. The longer blue line was the time when the plane was going to be painted.
Below is a video showing the painting of a Boeing 747 (the new Virgin Atlantic emblem).