|You can often change brightness settings in a game's settings, so you may be able to change color settings as well. However, since your monitor is 5 years old, that probably won't help, even if that's there. |
The most likely cause of that red tint is the backlight is in the process of burning out. It's a CCFL - Cold Cathode Florescent Lamp - like all florescent lamps, it slowly gets dimmer as time goes by, and eventually it burns out. You often get an overall tint of the display, often red, in the later stages of the backlight burning out process.
Also, as time goes by, the default settings of the OSD of the monitor get out of adjustment - don't use the "Factory" or similar settings when the display is an older one - you can probably get a better result adjusting settings manually.