Disclaimer: Yes, I am a science fiction geek, and I love anime, so noting that my suggestion would lead to buildings that look like they're from science fiction or anime is not a real objection in my book.
Basically, I'm thinking designers of tall buildings need to start considering using anodized, dyed metallic elements in their facades - kind of like flashy rims on a car or bicycle, only a lot bigger and in more elaborate patterns. Think about it:
http://www.independentcoatings.com/i...s_example2.jpg
http://www.myriadminds.com/tsj/trikd...ront2-1024.jpg
http://vfrworld.com/photos/data/500/..._Gold_Rims.jpg
http://image.made-in-china.com/2f0j0...-Carabiner.jpg
I'm thinking especially about the blue from that last link - I want to see that in huge, sky-high sheets with razor-sharp patterning. Stone masonry, brick, cement, plain steel / chrome, and now glass have been well-explored to date, but colored metal has not been. Where are the shiny, electric metallic blues and reds? Where does the cyberpunk aesthetic collide with the Industrial Age? I don't think you can deny this holds some pretty awesome possibilities.