I did the background with Ecoline's liquid watercolors (yellow, magenta, blue, turquoise and a hint of green and black) and I mixed a couple of them with a pinch of Schmincke's Aqua Bronze powders (silver and gold) to get some shimmer in them. 

Buildings I painted with a piece of plastic I had left over from some crafting, and Daniel Smith watercolor tubes (Quinacridone Burnt Orange and Carbazole Violet). 

This was so much fun and I'm positively surprised by my results! Thanks Jacqueline! :)