A cross-over feasibility trial of smartphone grayscale mode in medical students

Smartphones are central to digital health environments, yet their color-rich interfaces may increase visual salience and habitual engagement. Grayscale mode removes color saturation, potentially reducing attentional capture during digital task use.

We conducted a cross-over feasibility trial involving first-year medical students at an allopathic medical school. Participants were assigned in a 1:1 alternating sequence based on order of enrollment to use either grayscale screen settings or standard color display for one week, followed by a crossover to the alternate condition for a second week. Participants recorded daily screen time using their smartphone's built-in tracking feature and completed end-of-week surveys assessing attitudes regarding sleep quality and productivity. Linear mixed-effects models were used to analyze differences in screen time between conditions.

Fifty-one participants completed the study. Grayscale mode was associated with a statistically significant reduction in mean daily screen time compared to color display (mean reduction 28 min per day; p < 0.05). The effect was consistent across intervention order. Qualitative comments suggested reduced habitual engagement alongside usability challenges for certain tasks.

Grayscale mode represents a low-cost, scalable interface-level intervention associated with reduced smartphone screen time. These findings provide preliminary evidence that modifying visual features of widely available consumer technology may influence digital engagement patterns in high-demand learning environments.