A Perfect Love Story where nothing goes wrong or does it..?

Once upon a time there was a couple. They lived in a black and white winter reality. HE was a charming French photojournalist and gentleman, while SHE was a young and restless Bosnian artist. One morning, they left their gray smog reality in their nouvelle-vague old-timer. They passed through a tunnel and found themselves in a colorful summer reality. On the road to the coast, their relationship is constantly questioned. Finally, in this very Paradise-on-Earth, does their love come to an end.