Barbara Diethelm was born and raised in Zürich. After attending college in Zürich she moves to the United States in 1982. 1983 – 1988 Studies Graphic Design and Fine Art (with Mel Casas, Mark Pritchett und Tom Willome) at S.A.C. in San Antonio, Texas. Studies Humanities and Management at St. Mary’s University, San Antonio. 1988 – 1990 studies Painting (with Sam Tchakalian und Ivan Majdrakoff) and Printmaking at the San Francisco Art Institute, San Francisco, California. Beginning of the intensive study of Eastern philosophy and the way of yoga. 1990 returns to Switzerland. 1992 encounter with Agnes Martin and a longer visit with her in New Mexico. 


1994 receives an art grant of the State of Zürich. 1995 after her father's death, takes over the leadership of the family business Lascaux Colours & Restauro where she develops holistic colour systems. At the same time continuing to develop her painting in various working groups. 2004 founded, together with her husband the painter Werner Schmidt, the charitable foundation Fondation Lascaux, which focuses on the importance of colours for the emotional-spiritual consciousness and its relevance to a new, holistic view of culture, science and economics. She lives and works near Zürich, Switzerland.