63. Station Colors
There is a certain industrial feel to the subway stations. Some stations, like Union Square, are completely gorgeous in their layout and design, and the new stations, like Fulton Center, are incredible in their scale & move towards a friendlier environment.
However, many stations could benefit from some color, namely the color of the lines they represent. BDFM could be painted in brilliant Pantone 165, and the 7 line could have swirls of purple throughout the line, adorning walls and columns alike.