In 2020, researchers Holte and Ferraro published a study titled "True colors: Grayscale setting reduces screen time in college students" in The Social Science Journal. It was the first large-scale empirical study to measure the direct effect of greyscale mode on smartphone usage.
What they tested
The researchers asked college students to switch their smartphones to greyscale for a set period and tracked their screen time data. The goal was to find out whether removing colour from the phone display would change how much time students spent on their devices, and whether it would specifically affect social media usage.
What they found
The results were clear. Participants who used greyscale reduced their daily screen time by an average of approximately 38 minutes per day. Social media usage also dropped, because the visual rewards of colourful icons, feeds, and notifications became less stimulating when displayed in shades of grey.
The study suggests that colour acts as a form of visual reward. App designers use bright colours, red notification badges, and vibrant imagery to grab your attention and pull you back into the app. When those signals are removed, the pull weakens.
Why this matters for everyday phone habits
38 minutes per day adds up to over 4 hours per week and more than 230 hours per year. That is real time you could spend on other activities. And this reduction came from a single, low-effort change: turning the screen grey.
The study did not ask participants to delete apps, block websites, or follow complex routines. Greyscale worked as a passive intervention. It required no ongoing willpower or daily decisions.
How colour creates reward loops
Colour is one of the fastest channels the brain uses to evaluate whether something is interesting or rewarding. Social media apps know this. That is why notification badges are red, why photo feeds are saturated, and why app icons are designed to stand out on your home screen.
When you switch to greyscale, those signals lose their visual punch. A red notification badge becomes a grey circle. A bright Instagram feed turns into a flat set of grey images. The content is still there, but the automatic pull to keep scrolling is reduced.
Limitations to keep in mind
This study focused on college students, a group known for high smartphone usage. The effect size might differ for other demographics. Greyscale also does not address all reasons people use their phones. Functional tasks like navigation, messaging, and work-related use are less affected by colour removal.
That is why combining greyscale with smart exceptions for colour-dependent apps makes the approach more sustainable. You get the screen time benefits without making your phone harder to use for legitimate tasks.
How StayGray builds on this research
StayGray was designed to make the findings from studies like this one practical for daily life. Instead of asking you to dig into accessibility settings every time you want greyscale, the app gives you one-tap control, app-specific exceptions, time-based schedules, and timed colour breaks. The goal is to make the greyscale intervention as low-friction as possible, which is exactly what the research supports.
Reference: Holte, A. J., & Ferraro, F. R. (2020). True colors: Grayscale setting reduces screen time in college students. The Social Science Journal, 60(2), 274-290. doi.org/10.1080/03623319.2020.1737461