Researchers often turn to post hoc statistical techniques to identify common method variance (CMV) in same source data and one viable option is to use a marker variable. The choice of marker variable is important, yet these variables are difficult to find, primarily because they must be theoretically unrelated to study variables but measured in the same way (e.g., perceptual; on a Likert scale). This manuscript uses scale development best practices to create a marker variable—attitude toward the color blue—that can be applied in a wide variety of social science research. Scale reliability and validity are addressed, discriminant validity with other measures that detect CMV is tested, and the Confirmatory Factor Analysis Marker Technique is applied with this scale. An experiment designed to analyze the effect of the placement of the scale in surveys is reported. Recommendations to researchers for use of this new scale to detect CMV are provided.