I'm not sure if the problem I'm having has something to do with using Linux since I just experienced this problem about a month after getting Linux. My problem is that the colours on my monitor are all messed up. everything that's sapposed to be grey is pink, everything that's sapposed to be white is blue and a bunch of other colours. The most annoying part is all the texts are blurry but still read-able and I can't view videos(they just show up as a black square). The problem has nothing to do with my monitor, I've tried plugging my other computer is to this monitor and it worked fine. Can somebody please help me fix this explaining with a answer I can understand? sorry I'm not much of a computer person.
If it were a CRT monitor, I'd have advised beating the everloving crap out of it. That used to always solve my funky colour problems on those old heaps of crap. Either way, your problem sounds VERY much hardware related... Is the cable completely secure on both ends, and is the card fully pushed in on your motherboard? Bad connections can sometimes have strange results. Try swapping the cable itself too... Is the fan spinning on your video card? Overheating can cause all sorts of unexpected grief with the display. Have you tried booting a different live CD to isolate whether it is your install got corrupted, or a hardware fault?
Your video card is probably borked or on its last legs. Get a hold of another video card if you have any old ones lying around and try using that, or borrow one from a friend. Someone almost certainly has an old card buried away somewhere you can use. Out of curiosity, have you had it overclocked at all? I once got some really trippy things like you describe happening from pushing one just a bit too far for a bit too long...