computers

if u have an omd monitor then some things on the electronic plate is burned or your cabel (stekker) is not good,look at the pins of your plug and see if there all there or straight if some is broken u need to fix the plug else u need to buy a new screen or if in waranty enter in the shop DONT try to open your monitor yourself. There's a high voltage on your monitor even when it's unplugged, if u do want to open it unplug it for a half day then open it so the voltage isn't loaded on the screen

Your monitor is problematic...Probably because its old? Is it under warranty? If its under warranty, you can get it fixed for free... Otherwise you may have to get a replacement

Are you referring to your monitor? or are you referring to your casing ? or your desktop settings? etc

Do you mean the background. The desktop color. Or that everything is tinted. IE pictures and things that should be blue have turned green? A lot of things can happen to qa monitor. A magnet can cause discoloration on a portion of the screen. But only a portion. Some monitors have a setting for tint. Someone could have accidentally off set the color. Video board which sends graphics to the screen could be failing. Or the cord that plugs into the back of computer or monitor could be slightly ajar or bad.Lots of reasons.