To refinish the columns, the masons first coated the brickwork with a whitewash pigmented with titanium dioxide.  Titanium dioxide is a fairly modern pigment that is commonly used in most white paints produced today.  However, the pigment was not used in commercial paints until ca. 1921, so by adding the pigment to the columns’ whitewash, future restorationists will be able to quickly and clearly determine it was added to the columns as part of the ca. 2004 restoration effort.