On the portability of computer-generated presentations: The effect of text-background color combinations on text legibility

Objective: The aim of our study was to investigate which text-background (TB) color combinations improve legibility and pleasantness of texts either presented on a computer screen or projected on a wider surface. Background: Our work stems from the observation that multimedia presentations, even those by professionals in visual disciplines, are often spoiled by illegibility, which affects readability and the pleasantness of attending to such presentations. Methods: We investigated this problem through three experiments. Experiment 1 assessed the best TB color combinations in slides presented on a laptop. Experiment 2 verified the correlation between legibility and pleasantness for TB presentations. Experiment 3 investigated the legibility of a slide projected on a wide screen in different room lighting conditions. In all experiments participants expressed a rating score for stimulus legibility or pleasantness. Results: Experiments I and 3 showed that it is best to have a dark text on a light background for both displayed and projected texts. Experiment 2 showed that pleasantness is tightly correlated with legibility, though legibility depends on contrast between text and background. Conclusions: Our findings are not in complete agreement with the literature concerning legibility of text displayed on a computer screen, and they are in contrast with the common belief that for projection purposes it is best to have a light text on a dark background. Applications: Some practical rules on combining TB colors are given to enhance the legibility of presentations, especially important for the legibility of projected texts.