OnDesktopOverlay is a simple portable option to add a colored overlay to your screen to help prevent eye strain.
You several color options to choose from with the default being set to red. Any color chosen can be altered via the opacity slider to fine tune it to your preference. There is also the option to create a custom colored overlay. You can access that and the other preset colors by right-clicking the systray icon.
OnDesktopOverlay is a simple-to-use app that will be helpful for those long sessions spent staring at your monitors and the fact that it is portable makes it a great choice to help relieve eye strain no matter where you are.