## 5 Conclusions  
In our study, the combination of achromatic text on a chromatic background emerged as the most effective combination for enhancing the legibility of promotional text. This suggests that when the primary goal is to maximize reading efficiency, this particular pairing has the potential to provide an advantage. This can serve as a valuable guideline for designers when creating promotional materials for environments with limited reading time. In brochures, where space is constrained, designs that enable quick reading ensure that relevant information is visible and engaging. In busy settings like trade fairs or digital ads, effective color combinations reduce cognitive effort, making messages easier to process. However, if the aim is instead to ensure a clear comprehension of the promotional text, the color combination has a less critical role. In such cases, designers have the flexibility to choose from any of the color pairings tested in our study, as the comprehension levels remained consistent across these variations. This may be particularly effective when the chosen colors align with the visual identity of the product, enhancing brand recognition and consistency. The lack of interaction effects in our study suggests that the participants' responses were unaffected by the choice of medium, given that their reading performances were consistent across both print and digital presentation of promotional text.  
This study has certain limitations. First, the participants were mostly students, with a small number of faculty members from the Faculty of Graphic Arts. Future research should include a larger and more diverse sample of participants from different cultural and educational contexts to enhance the applicability of the results. Second, our guidelines for designers apply only to specific color combinations, and future research should expand the range of colors, and their combinations tested for legibility. Third, given that some studies indicate differences in text legibility within digital media [46], our future research could also focus on comparing legibility across paper, computer, tablet, and mobile device. Nevertheless, our research provides insight into the potential effectiveness of combining achromatic and chromatic colors, particularly when the goal is to reduce the time required for reading. In the context of product promotion, reduced reading time could allow consumers additional time to focus on the product itself or to review other relevant information necessary for making informed and thoughtful purchase decisions. In future studies, alongside exploring color combinations, it would be valuable to investigate other elements of promotional text, such as the type and size of typography, to further optimize the reading experience.  
Conceptualization, P.B. and D.K.; methodology, P.B., D.K. and R.K.; software, D.K., R.K. and P.B.; validation, D.K., P.B. and R.K.; formal analysis, R.K.; investigation, P.B.; resources, R.K. and P.B.; data curation, D.K. and R.K.; writing--original draft preparation, P.B.; writing--review and editing, D.K. and R.K.; visualization, P.B. and D.K.; supervision, D.K.; project administration, D.K.; funding acquisition, D.K. and R.K. All authors have read and agreed to the published version of the manuscript.  
The APC was funded by the University of Zagreb.  
The study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Ethics Committee of University of Zagreb Faculty of Graphic Arts (date of approval: 10 October 2024).  
**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.  
**Data Availability Statement:** The data presented in this study are available upon reasonable request from the corresponding author. The data are not publicly available due to privacy.  
**Conflicts of Interest:** The authors declare no conflicts of interest.