Purple Overlay on Monitor

Hardware Hub GPU
1

I turned off my PC, and connected the HDMI from my PC to my xbox to play on my monitor. Later, when i reconnected my PC, the screen has a purple overlay. I have tried connecting and reconnecting the HDMI, and restarted the PC, and uninstalled the driver and installed them again, nothing worked. I connected the xbox back in and the color was fine, The windows 8 logo is in normal color when the PC boots up then turns purple. I have a Radeon HD 6870 graphics card. (its old, I know) Anything would help

Thanks

2

Check the cable.  I had the same thing when using a vga and it wasn't pushed in all the way.

3

Is it not displaying the color green? If it's not there is a problem with the connection or the cable. This happens to vga if it's not plugged in all the way.