Train rail sequence = three strip filming

There is a sequence in Daisies where the camera shoots train tracks as the train moves. There is color in the film that i think is based on the speed of the image? I think this may be the most beautiful thing ever shot... and I'd like to know how they did this.

If anybody out there has any ideas as to what film stock this was. Was this an in camera trick or in post? Was this some form of three strip technicolor?

Let me know if you can shed any light.