RedLight

RedLight is a lightweight Windows utility that applies a customizable full-screen color filter. It is designed to help reduce eye strain or assist with accessibility.

Download

You can download the latest (RedLightForWindows.exe) from the Releases page.

Features

• Full-Screen Filters: Apply various color matrices to the entire screen using the Windows Magnification API.
• Filter Modes:
  • Red: Reduces blue light, ideal for night usage.
  • Grayscale: Converts the screen to black and white.
  • Color Blindness Simulations: Protanopia (Red/Green), Deuteranopia (Green/Red), and Tritanopia (Blue/Yellow).
• Adjustable Intensity: Fine-tune the strength of the filter using a slider.
• Tray Popup: Lives in the system tray; click the icon to toggle a popup with all controls.

Requirements

• Windows 10 or Windows 11

Usage

1. Run the application. It starts in the system tray.
2. Click the tray icon to open the popup.
3. Check Enable Fullscreen Filter to start.
4. Select a Filter Type from the dropdown.
5. Adjust the Intensity slider to control the effect strength.
6. Click outside the popup to dismiss it. Click Quit to exit.

Stack

• Framework: .NET 10 (WPF & Windows Forms components)
• API: Windows Magnification API (MagSetFullscreenColorEffect)