The rainbow (if it appears at all on March 2nd) would likely appear as a spectrum of colour ranging in sequence from Red-Orange-Yellow-Green-Blue-Indigo-Violet.
Since there needs to be liquid water in the air (rain, mist, dew, etc) for a rainbow to form, it might be hard to find one on March 2nd very far north of South Carolina.
Another problem that arises is that there is no train track between Canada and South Carolina capable of supporting a train at 400 mph.
