computer keeps crashing while playing games to a random solid colour

[iou64]

when ever i play a game i will be able to play for about 5 mins before my pc crashes to a solid random colour that changes every time. i only got the pc at christmas it was custom built and it has always happened but is starting to happen alot more then it used to i have an i5 4690 16gb ram gtx970 when i am using a tv to play games and it says that the native resolution is 1024 x 764 or something like that but i play it at 1920x 1200 im not sure if this has anything to do with it and thought that i would just put it in i have no idea why it is doing it the computer usally restarts itself after crashing. 

[Altecice]

What are you full computer specs?

[iou64]

 CPU: Intel i5 4690 3.5Ghz Quad Core 

CPU Cooling: Zalman x5 Performance Heatsink & Fan 

Memory: 16GB DDR3 1866Mhz Vengeance (8GBx2) 

Motherboard: Gigabyte B85 with USB 3.0 Support 

SSD Hard Disk: Optional Extra 

Hard Disk 1: 1 Terabyte UDMA600 

Hard Disk 2: Optional Extra 

Optical Drive: LiteOn 22X DVD Rewriter 

Video Card: NVIDIA GeForce GTX 970 4GB 

Sound Card: Realtek ALC887 8-Channel HD with BluRay Support 

Wireless: Optional Extra 

Power Supply: FSP 500 Watt 80+ SBronze Certified PSU 

Operating System: Windows 8.1 Standard 64 Bit 

[00RaZoR11]

when ever i play a game i will be able to play for about 5 mins before my pc crashes to a solid random colour that changes every time. i only got the pc at christmas it was custom built and it has always happened but is starting to happen alot more then it used to i have an i5 4690 16gb ram gtx970 when i am using a tv to play games and it says that the native resolution is 1024 x 764 or something like that but i play it at 1920x 1200 im not sure if this has anything to do with it and thought that i would just put it in i have no idea why it is doing it the computer usally restarts itself after crashing. 

My system does this color flickering thing when I OC my gpu to an unstable speed.

In my PC's first few days, I had an issue with proper power delivery (too weak PSU and shitty MoBo), which caused it to crash a lot, even at idle. However I don't see how this could be a problem in your config, just saying.

That TV might not have high enough resolution -maybe it's old- , hence the "native resolution is 1024*764" stuff. It's just low res (feel free to correct me if I'm wrong).

You could try to play at a resolution as low as the TV's or try a different screen that was actually designed for use with computers.