The background of my monitor keeps changing colour. First it went yellow then blue. It's across all applications and is not the monitor as it has now reoccured on 2 different monitors.

Check the connections on the 15-pin cord connecting the monitor to the video card. Look for bent or missing pins. Note pin #9 is supposed to be absent.

Update your monitor driver.Update your video card driver.Check your monitor settings.Try 16 bit color,then 32 bit color.Update all drivers on your PC.Maker sure your graphic card is compatible with your PC 'spec'.Set your screen resolution to 800x600,then to 1024x768.I'm assuming you have a CRT monitor.See if changing those settings make any difference.

If it's LCD or TFT,again check all the settings,which I'm sure you've done anyway,but sometimes a second,or even third try can do the trick.

If all that fails,visit www.benchmarkhq.ru/be_monitor.html

Scroll down the page till you see 'Monitor Calibration Wizard'.

Read the info,then download the freeware tool.I have it installed on my PC running XP,and have had no problems with it.

All the best,
Nez.

Or better still,follow the advice by the moderator :D

Just checked pin all 15 pins are there! Including No 9 - could this be the problem
If so what is best way to remove it and exactly which one is No 9

Just checked pin all 15 pins are there! including No 9 - could this be the problem
if so what is best way to remove it and exactly which one is No 9

No... some cords include all 15 pins. This is not the problem... don't yank the pin. :)

That happened with my video card once. The cord was weighing it down. If you hold the cord in place does it go back to normal color. If it does you might want to get some cable ties with those little sticky things so it doesn't get loose and change the color on you.

My tuppence worth, When you get the wrong colour, GENTLY manipulate the able that goes into the monitor and if it is not that then try the plug end as well.

If this has no effect and if it is not the video card (they are normally very reliable) the it is probably the electronics on the monitor.

BTW, if while manipulating the cable on the monitor side and the colour comes back, this could be either a cable problem or a dry joint maining /loosing contact due to microscopic movement/heat