Once the panels were completed, they were hung on tracks over the south elevators and bonded together with fibreglass and resin to form a single slab. The finished work is 4.57 m high by 22.86 m wide and weighs approximately 1,360 kg. It took the artist six months to produce the mural in the basement of the head office building.

Like a stained glass window that becomes luminous when light passes through it, the mural is illuminated by a system of back lighting made up of 1,280 m of neon tubes in eight different colors. If the mural were lit by a single source of white light over its entire length, one would see only the pigment of the fibreglass itself. With the addition of seven other hues, each of these, on its own, alters the shades and even the colors of the mural. For example, a yellow light turns the mural's blues to green, the greens to chartreuse, the reds to an orange shade, and so on. Each change of source color creates a new picture, in a way.

As a result of the circuit arrangement, the gradation in the brightness of each group of circuits, the variations in transformer voltage and the length of the luminosity cycles, the plays of light constantly overlap, producing a nearly infinite variety of effects and colors, and virtually perpetual change in Mousseau's mural.

Unveiled in October 1962, in the presence of dignitaries including René Lévesque, then Minister of Natural Resources, and Georges-Émile Lapalme, Minister of Cultural Affairs, the mural would illuminate the lobby of Hydro-Québec's head office for close to 20 years before its lighting system failed.