The Blue, Screen of Death and the Black and Yellow Screen. are most commonly known But did you know that there were also Purple, Red, Green, Brown Screen of Deaths also present and that it is possible that there is software on you computer that can create these various colour screens and the related problems.
There is no one particular factor that causes these events it can be hardware or software.
The screen colour does however give an indication to any technical staff involved in addressing the issues with your hardware and software problem