This study examines the effect on mail survey response rates of variations in questionnaire color and format. A follow-up mail survey to a corporate incentive program was sent to more than 3,500 participants. Monitoring response rates by questionnaire version showed that a user-friendly format, followed by a two-color design, significantly increased response rates. Question wording and sequencing remained the same across questionnaire versions while format and color varied. A literature review revealed three issues addressed by past studies—structural, functional, and incentive—that impact response rates. Previous studies have found no response rate increases due to altering the color of a questionnaire. However, this study found that a user-friendly format, and to some extent color, was valuable for increasing mail survey response rates. Implications for writers of all forms of communication are drawn.