So after 30 or so minutes of playing, some random texture will, I guess, "corrupt" and will become rainbow and pixel-y, and I have to restart the game if I want it to fix, but then it wills soon happen again, so any ideas will help.

I play Fallout on console, but that sounds awfully similar to a problem I get on my PC when my graphics card is too hot or overworked.

My PC is cool to the touch as I am playing though.

Is your GPU an AMD?

Seems to be a widely reported issue post 1.3

There is a recent thread about that issue here.

http://www.gamesas.com/topic/1590000-fix-the-13-graphics-bomb/