For over 20 years all Diesel collections, including licensed products, were made under the Creative Direction of Wilbert Das. Currently the principal lines are Diesel, the main line, and Diesel Black Gold, a new collection launched in 2007 in the casual-luxury segment.

Das has worked for Diesel since 1988. Wilbert started as a designer on the Male, Accessories, Leather, and Kids lines. He rose quickly to head the style office and creative areas of Diesel, and in 1993 was given the official title of Creative Director, with responsibilities ranging from directing all product design as well as all communication campaigns. From clothing and accessory design to advertising, new media, merchandising, retail and interior design (including stores, showrooms, offices, hotels), planning of fashion shows and events, as well as developing new brand extensions such as houseware, furniture and even automobiles. Literally all aspects of the Diesel brand's style and image fell under Wilbert's responsibility.

Wilbert Das left Diesel in late 2009 amid rumors of irreconcilable differences with CEO Rosso over the future direction of the company.
In 2010 the new creative direction was given to the french fashion founder of WAD Magazine (We Are Different), Bruno Collin.

–source wikipedia.com