I love Proton's commitment to privacy, but the current 8 preset themes are very limited. Everyone has different visual preferences, what looks sleek to one person might cause eye strain or feel cold and sterile to another.

I would love to see a Custom Theme feature added to the settings. Instead of just adding a few more presets, allow users to pick their own accent colors and background shades with a simple color picker or hex code input.

This would benefit everyone: it gives users the freedom to match their interface to their personal style, and it makes the platform much more comfortable for prolonged use for people with visual sensitivities or neurodivergence. A fully customizable theme system would make Proton feel truly personal and user-first.