A pure red screen to test the red subpixels, use as a dim night light or as a colored backdrop for photos and video.
When time is up, full screen closes on its own.
Put a white or warm screen in front of you and turn up the brightness. It lights your face softly, like a ring light.
Black shows dust, white shows smudges. Use both and nothing gets missed.
Cycle through red, green, blue, white and black. A dot that doesn't change color is a dead or stuck pixel.
A soft color at low brightness works as a night light or for reading without turning on a lamp.
To check the red subpixels and find dead pixels. At low brightness it also works as a night light that's easy on the eyes.
Dim red light affects sleep less than white or blue light. Keep the brightness low and don't stare at it up close.
Show red, then green, then blue. If a dot looks black or a different color on any of them, it's a faulty pixel.