Pick one app screen, screenshot it as it normally appears, switch to dark mode and screenshot it again, raise system text size to maximum and screenshot once more. Sets with fewer than three variants or different screens are sent back, and each contributor submits one set, so apps, phones and OS versions vary across a global base. No element annotations, but the triplets are self-labeled by construction: same content, known transformation. Dark mode changes most interface colors and a large accessibility font reflows the layout, truncates labels and pushes controls off screen; GUI models are brittle there, and we know of no controlled dataset of one screen under those settings.