 David Childs of Skidmore , Owings and Merrill worked in conjunction with glass artist and designer James Carpenter to create a design that uses ultra @-@ clear , low @-@ iron glass to provide reflectivity and light , with stainless @-@ steel spandrels behind the glass to help reflect sunlight . Stainless steel used in the building façade is molybdenum @-@ containing Type 316 , which provides improved resistance to corrosion . To enclose the power substation and improve its aesthetics , the base of the building has a curtain wall with stainless steel louvers that provide ventilation for the machinery . During the day , the curtain wall reflects light , while at night it is illuminated with blue LED lights . The curtain wall around the lobby uses heavily laminated , heat @-@ strengthened glass that meets high standards for blast resistance . At night , a large cube of light above the lobby also emanates blue light , while during the day it provides white light to the lobby , and at dusk it transitions to violet and back to blue . Inside the main lobby , artist Jenny Holzer created a large light installation with glowing text moving across wide plastic panels . The entire wall , which is 65 ft ( 20 m ) wide and 14 ft ( 4 @.@ 3 m ) tall , changes color according to the time of day . Holzer worked with Klara Silverstein , the wife of Larry Silverstein , to select poetry for the art installation . The wall is structurally fortified as a security measure . 
