atmospheric density in exhibition spaces. In Room For One Colour (1998), a corridor lit by yellow monofrequency tubes, the participants find themselves in a room filled with light that affects the perception of all other colours. Another installation, 360 degrees Room For All Colours (2002), is a round light-sculpture where participants lose their sense of space and perspective, and experience being subsumed by an intense light. Olafur's later installation Din blinde passager (Your blind passenger) (2010), commissioned by the Arken Museum of Modern Art, is a 90-metre-long tunnel. Entering the tunnel, the visitor is surrounded by dense fog. With visibility at just 1.5 metres, museumgoers have to use senses other than sight to orient themselves in relation to their surroundings. After attending the 2019 In real life exhibition, Souter deemed Your blind passenger one of Olafur's finest works, reporting that she felt "alone in the universe. [...] I thought I could see my own irises, flashing as a ring of blue in front of me, and I could hear my own heartbeat in my ears." For Feelings are facts, the first time Olafur has worked with Chinese architect Yansong Ma as well as his first exhibition in China, Olafur introduces condensed banks of artificially produced fog into the gallery of Ullens Center for Contemporary Art, Beijing. Hundreds of fluorescent lights are installed in the ceiling as a grid of red, green, and blue zones. Green river In 1998, Olafur discovered that uranin, a readily available nontoxic powder used to trace leaks in plumbing systems, could dye entire rivers a sickly fluorescent green. Olafur conducted a test run in the Spree River during the 1998 Berlin Biennale, scattering a handful of powder from a bridge near Museum Island. He began introducing the environmentally safe dye to rivers in Moss, Norway (1998), Bremen (1998), Los Angeles (1999), Stockholm (2000) and Tokyo (2001) — always without advance warning. He first achieved international prominence with Green river, which initially made Stockholm pedestrians concerned that the city's water had been tainted. A Riverbed Inside the Museum At Denmark's Louisiana Museum of Modern Art in 2014–2015, Olafur created a riverbed installation. He compiled natural rocks, dirt, and water to transform the gallery space into a landscape and titled the piece, “A Riverbed Inside the Museum.” Olafur captures physical phenomena in a way that appears both real and slightly artificial, while contained in a constructed space that