The Arch's Colorful Companions

I took the photos below on June 2, 2017 and June 5, 2017.  They show mysterious orbs above an arch at one end of Grand Central Terminal in New York. I get these colors a lot -- along with purple orbs by the hundreds (as shown here).

Near the top of the same arch, I photographed this mysterious orb on March 28, 2017. Somehow the little shape inside the orb reminds me a bit of a bas-relief artwork of a human figure.