The varied architecture of the buildings of New York is fascinating, to say the least. Nonetheless, one salient quality of several buildings such as the UN Building, the Seagram Building, and the Lever House are the tinted glass of green, blue, and brown that cover at least one wall. So, these skyscrapers seem like giant votive candles to the altars of commerce and power. Votive candles are contained in tinted glass containers; the candles are lighted as intentions for prayer on behalf of the needs of a person. These candles are lined up before an altar where there is often a statue or picture of a figure connected with the religion to which the votives are associated.
With respect to the Seagram's Building which has a curtain of "whisky-brown" glass:
The building was, notably, the first with floor-to-ceiling windows, making the wall a true curtain of glass....
Here, another idea is also the disguise of these buildings that can be used metaphorically as they appear to be mirroring the other buildings, cars, and people near them, reflecting the hustle, the avarice, the cupidity of a commercial world.