Running through Full Spectrum, the latest group exhibition at the Pittsburgh Glass Center, is an odd motif — bananas. Whether or not the fruit appears intentionally or not remains a mystery, but it definitely stands out, whether in the work of Caymanian-American artist Davin K. Ebanks, as a noted inspiration of Korean-born artist Eun-Ha Paek (their statement references “a banana peel on the floor”), or in the bright yellow bunch that appears as part of Nikki Lau’s ceramic Chinatown-inspired cornucopia.…