Decided to sit with this one for a while. Got the grain from the 800 ISO film. This is a reflection in the metal surface of an escalator. I made a layer cake out of it in photoshop:
5. Circular gradient overlay. The gradient was a magenta to magenta, 0 to 100 % opacity layer set to "Overlay" blend mode, and then set to a 70% opacity. I wanted to bring out the magenta tones that were already available near the bottom of the picture.
4. Curves - a slight revers "s" on the Red channel.
3. Duplicate of the original layer, set to Colour Burn and 65% opacity.
2. Levels - slight bias towards white and washed out. (this plus the colour burn seems to give a more "colourful" intensification than simply bringing in the sliders on a Levels adjustment at both ends, or simply colour burning by itself). I might be way wrong about this though.
1. Original photo.