Dan Flavin, untitled (in Honor of Harold Joachim) 2, detail, 1977, Tubes fluorescents : rose, jaune, bleu et vert, 122 x 122 cm, Photo. Fabrice Seixas © Dan Flavin/ ADAGP, Paris 2015, Collection FRAC Nord-Pas-De-Calais, Dunkerque, France, Courtesy the artist