Halloween usually calls for frightening, creepy costumes, like skeleton makeup or Pennywise clown looks, but this year, step out of the box with something more creative like a pop-art costume.

One of the many good reasons to see the exhibition of Roy Lichtenstein’s pre-Pop-art work, “Roy Lichtenstein: History in the Making, 1948–1960”—which originated at the Colby College Museum of Art in ...