This chapter presents a study that investigates the effects of mobile website design on the behavioral intentions of adult consumers. More specifically, the authors analyze the interaction effects between the principal design cues of a mobile commerce (m-commerce) website, such as background/foreground colors, font text and layout. A website selling music CDs has been especially designed and built for the experiment in order to place participants in real-life conditions of navigation. Three experiments have been conducted based on visits to a fictitious m-commerce website. Experiment 1 manipulates the levels of color contrast: positive contrast (light text on a dark background) versus negative contrast (dark text on a light background). In experiment 2, contrast and font have been manipulated with a complete factorial plan: 2 x 2 (negative vs positive contrast x serif font vs sans serif font). Finally, contrast and layout have been manipulated in a third experimental 2 x 2 plan (negative vs positive contrast x dense vs airy layout). This research involved 219 French participants over the age of 45. Results show significant effects of the positive contrast (light text on a dark background) of the mobile website design on the purchase and revisit intentions of adults. Discussions about the interaction effects of design elements, limitations and directions for future research follow.