A developer analyzed MacOS screenshots from 2009 to 2025, finding the default light mode UI has steadily brightened to 100% average lightness. Using Python and image processing, the data shows a clear upward trend in window chrome brightness, with the darkest elements in modern versions now brighter than the brightest parts of older systems.

This gradual brightening, or UI inflation, likely stems from designers favoring brighter visuals. The author notes this trend accelerated with macOS Big Sur in 2020, pushing them to switch to dark mode permanently. The advent of HDR screens in iOS 26, which can display elements brighter than 100% white, threatens to exacerbate this issue further.

For developers and designers, the study raises questions about user comfort and visual fatigue. The author suggests resisting the urge to constantly brighten interfaces and proposes a return to medium-grey themes for better contrast and eye strain. The trend highlights a broader design challenge: balancing aesthetic appeal with practical readability.