Color psychology explores how colors influence emotions and behavior. In graphic design, color choices can impact brand perception, user engagement, and overall effectiveness. To test the effectiveness of color psychology, designers can use A/B testing by creating multiple versions of a design with different color schemes and measuring user responses through metrics such as click-through rates, time spent on a page, and overall user satisfaction. Additionally, surveys and focus groups can provide qualitative insights into how different colors affect user emotions and preferences.