Red Light Mode strict red/black
Entire UI rendered in red-on-black for darkroom use.
Where to find it
Settings Red Light
Summary
Red Light Mode converts every pixel on the screen to red-on-black using a color matrix filter, preserving night vision and film safety in a darkroom. The Android status and navigation bars are also hidden so no white pixels (the system clock, battery icon, gesture nav) leak through. The UI remains fully functional: you can still measure, adjust settings, and navigate, but only in red light wavelengths. Toggle in Settings under Red Light Mode.
Detail
How it works
What it does
Turn it on and the entire app — buttons, text, overlays, everything — turns red. Black areas stay black, white areas become medium red, gray areas become dim red. The math preserves perceived brightness so the UI is still readable. Android's own status and navigation bars (the white clock, battery icon, back/home/recents) are hidden too so no white pixels leak through; swipe down from the top edge to reveal them transiently if you need to check the time.
When to use it
Darkrooms and other situations where you need to preserve night vision. Red light is the longest visible wavelength; film is less sensitive to red light than to blue or green, so you can work safely without fogging your negatives.
Important note
Red Light Mode disables brightness lock. In a darkroom the ambient light is zero so auto-brightness is useless anyway; manually adjust your phone brightness to what feels safe for your film stock and keep it there.
What you can do in Red Light
Everything. Measure light, adjust metering modes, browse your shot log, check settings. The meter stays fully functional; only the colors change.