In my second visit to shoot that beautiful street, downtown London, having a tripod and cable release, I shot a whole role of film, trying to get one single shot at least where the traffic light trails, answers the curves of the building in the composition. This shot was one of the best of them, yet it came from the scanning with a deep purple cast, so I copied the Blue channel, and pasted it over the original layer in PS, changed the blending options to Luminosity, and this was the direct result I got.
I really think the composition of the shot is fantastic. The curve of the buildings helps to create that marvellous wedge of sky which I think is the best part of the photo. However, I think the color balance is still off. The building still have some of the purple hue which you referenced and the sky has a distinctly green cast, unless my monitor is screwed up. I think you can easily correct this further with your imaging software, or perhaps consider scanning it again. I think once the colors are brought under control, this will be a truly fantastic photo. Its still quite good.
0 
