This is how I started. An idea to make something very simple, as my client asked... yet it was too simple at the beginning. Very dull, foggy and after all not appealing. 

Less light made it stand out a little. At this point it was much better than before, but still not what I was looking for. It had some of dark vibe although it was too blue/cold toned and unfortunately decrease in saturation made it just dull and foggy. Even though the client wanted to keep it in gray colors I took one step further to make it more fun. Why not use christmas lights? :) That's how I ended up with results above.