Yves Klein, who once claimed the entire sky as his greatest artwork, patented his own pigment of blue, and used live naked women to paint some his most ingenious masterpieces, was arguably the most brilliantly creative artist of the 20th century.  On the 50th anniversary of Yves Klein’s death, two masterpieces by the artist will be offered in Christie's Post-War & Contemporary Art Evening Auction, London on 27 June. This follows the outstanding result achieved at Christie's New York last May when the legendary FC 1 (Fire-Color 1), painted only a few weeks before his death at the age of 34, using fire and his unique color of blue, sold for $36,482,500 (£22,619,150), setting a new world record for the artist at auction. Up for auction: Le Rose du bleu (RE 22), painted with illuminating rose cadmium and by far the largest pink sponge relief ever created and included in all the artist’s major exhibitions over the past 50 years, Relief éponge bleu (RE 51), the ultramarine blue sponge relief previously owned by Lucio Fontana, and Anthropométrie (ANT49).