Night Trains

Crossing above the Edinburgh train station on what I assume is the North Bridge, one can look off the bridge and see a lot of glass roof and some odd lights shining up through the glass.
There were blue lights, also, and a sort of orangey-green, but photos of those came out not so well as this one with the purple.
And here is another view from another bridge and what looks like an utterly prosaic platform, at least until one starts playing "count the layers of architectural revision". No obvious sources of weird purple lights.