A while ago, I posted a thread talking about a Team Fortress 2 Graphical glitch.
I have found out how to fix that if you have it.
This glitch causes rainbow-colored textures to replace nearly everything, excluding players and weapons.
TO FIX:
Make a script that plays any demo you want, and turns fullbright on at the same time. After tf2 is started, type exec (nameofscript) in the console.
Once the demo loads and everything is fullbright, type "stopdemo" in the console.
Play a game. It worked for me.
------------------------=-------------------------=------------------------=---------------------------
portal2
If you get this message in your console ***** Trying to set a pixel shader that failed loading!
and your screen is black, use this command:
mat_postprocess_enable 0
All for now.