## 1 Introduction
### Hypotheses  
Changing the background and text color can have varying effects on the legibility of promotional materials displayed on screens. Previous studies have shown that certain color combinations significantly affect character recognition and word legibility on video displays; black on yellow and green on white have been considered as highly legible combinations, while red on yellow, red on green, and green on red have been rated as the combinations with the lowest level of legibility [24]. In another study [2], among the combinations of dark text on a light background, black or dark blue text on a light background showed the best results in terms of legibility and user preference. High-contrast color combinations generally improve legibility by increasing reading speed and reducing the number of eye fixations. This effect is particularly notable with combinations like dark text on a light background, which the visual system processes more easily [10]. According to a study by [PERSON] et al. [18], color difference had a more significant role in legibility under conditions of low luminance contrast. In their study, [PERSON] et al. [25] examined how ambient lighting, color combination, sign height, and viewing angle affect the assessment of wayfinding signage legibility. Their findings indicated that achromatic color combinations were more legible than chromatic ones, although the difference was not statistically significant. [PERSON] et al. [26] concluded that cognitive performance can be significantly influenced by both color combination and luminance contrast. Based on these findings, the first hypothesis is proposed as follows:  
**H1.**: _There is a difference in the legibility of promotional text presented in different color combinations._  
Digital screens and printed materials are widespread in daily life, making it increasingly important to understand the differences in visual perception across these mediums. According to [PERSON] [9], the first century of legibility research focused on the practical effects of typographic attributes on reading, as well as on publishing economy. Nowadays, digital typographic resources enable greater precision and facilitate experimentation. Building on earlier studies, advancements in digital typography have provided novel perspectives and fostered a greater consensus on the impact of type size on reading, along with some concurrences regarding the effects of width and weight. Previous research [2, 10, 18, 22, 24, 25, 26] has focused on studying various color combinations of text and background in digital or physical media, and the extent to which these combinations (and their contrast) impact legibility. However, questions remain about whether certain color combinations of text and background affect text comprehension and reading time, as well as whether the medium itself influences this perception. Consequently, the study also explores the following hypothesis:  
**H2.**: _There is a difference in the legibility between promotional text displayed on a screen and that displayed on paper._  
Most existing research focuses either on individual color combinations on a single medium or on the impact of contrast without a comprehensive examination of the specific effects of color combinations in digital and print formats. Therefore, our study sought to compare the influence of various text and background color combinations on legibility and reading time across digital and print media. Particular emphasis was placed on how achromatic, chromatic, and achromatic-chromatic color combinations influence reading and text comprehension across both mediums.