However, a trip to the station let me know otherwise. The station is immaculate, and it's not dirt, but patina (http://en.m.wikipedia.org/wiki/Patina) that gives the station it's aged appearance. Much like the Statue of Liberty, these landmarks have aged to an intense green that L. Frank Baum may have envisioned when writing about the Emerald City in 'The Wonderful Wizard of Oz.'
Also, the station's interior has been masterfully restored. While smaller in scale, the beautiful Tiffany stained-glass ceiling rivals the beauty of Grand Central's starry fresco. Details about the restoration can be found here: http://en.m.wikipedia.org/wiki/Hoboken_Terminal