“By 1960 the nascent computer industry had delivered about 5000 computers in the United States and over a thousand to the rest of the world. Across the industrialised regions of the world computers were seldom seen devices. They hid, shrouded in mystery, like tall wardrobes, in large rooms where the air temperature had to be regulated so as to absorb the heat from the electronics that filled the block-like covers. The IBM 1620 was no exception. The company had earned the nickname “Big Blue” due to the pale blue covers that enveloped its machines. Located in the new Physics building on the west side of the campus, tended by a small group of academics and technicians, the UWA 1620 sat inert yet alive, a mystery waiting to be unfurled.”

—Alex Reid, from his internet-posted essay History of Me and Computers, chapter 4, Early Computing at The University of Western Australia. Alex is the only person on the internet who could explain to me why IBM’s nickname is Big Blue.