Font and background color combinations influence recognition efficiency: A novel method via primary color Euclidean distance and response surface analysis

The readability of human–computer interfaces impacts the users’ visual performance while using electronic devices, which gains inadequate attention. This situation is critical during high-stress conditions such as firefighting, where accurate and fast information processing is critical. This study addresses how font and background color combinations on Liquid Crystal displays (LCDs) affect recognition efficiency. A novel concept, primary color Euclidean distance (PCED), is introduced and testified under a repeated-measures experiment. Three factors were investigated: background color (black, white), font color (red, green, blue), and PCEDs. A total of 24 participants were recruited. Results demonstrate that color combinations with specific PCED values can substantially impact recognition efficiency. By using RSA, this study modelled the response time in a generalized mathematical model, which is response surface analysis. Results showed that blue font colors under a black background showed the longest response time. This study also explored the influence of physical stress on recognition efficiency, revealing a latency of about 100 ms across all color combinations. The findings offer a methodological advancement in understanding the effects of color combinations in digital displays, setting the stage for future research in diverse demographic and technological contexts, including mixed reality.