Red light and color field
Red Screen
Fill the display with red for a primary color check, a dark room task or a bold digital background. The page starts at #FF0000 and includes dimmer red presets for situations where full output is unnecessary.
- Starting red
- #FF0000
- Channel
- Red 255, green 0, blue 0
- Testing
- Red subpixel comparison
- Exit
- Escape or tap fullscreen
Use a Red Screen without losing control
Pure red is intense on many displays. Begin dim, then increase only if the task requires it.
Select a red
Use Pure Red for a channel test or choose a deeper preset for lower visible output.
Lower the light
Use Shade and the device brightness together when working in a dark room.
Inspect the panel
In fullscreen, scan the display for points that remain dark or show an unexpected color.
Compare other fields
Check green, blue, white and black before drawing a conclusion about a pixel.
Red light in a dark environment
Dim red light is commonly chosen when a person wants less bright white light in a dark setting. This page lets you reduce the digital red value, but comfort and visibility still depend on the display's own minimum brightness.
Do not describe any screen as guaranteed to preserve night vision. The result varies with intensity, exposure time, the viewer and other light sources.
Check the red channel without guessing
A full red field activates the red channel while green and blue remain at zero. A dark point can indicate that part of a pixel is not producing the expected red, but dirt or a surface mark can create a similar impression.
Clean the panel, repeat the observation on green and blue, then open pure black to look for pixels that remain lit.
Red screen settings
Use exact values for testing and softer settings for ambient light.
Red presets
Switch among pure, deep and dim red values prepared for different output levels.
Brightness steps
Reduce the selected red to a known percentage without changing to another hue.
Color comparison
Compare the previous red with the new value across equal halves of the display.
Image download
Create a flat red screen background at a common display or device size and download it as a PNG.
Important: A red screen is not safety equipment. Do not rely on it for navigation, emergencies, darkroom processes or any task that requires a specified lamp output.
Red Screen questions
What is pure screen red?
The Pure Red preset is #FF0000, or RGB 255, 0, 0.
Can I make it dark red?
Yes. Choose a darker preset, use Shade or enter your own HEX value.
Does red find every bad pixel?
No. It checks one primary channel. Use several solid colors for a more useful visual inspection.