A pixel sized phoenix down anyone?

[o_O]

You have a stuck pixel, not a dead one. A dead pixel appears completely black and cannot be fixed, but a stuck pixel is stuck in the "on" state and appears blue, red or green.

Sometimes doing what rubah said will fix it but I've had more success with the colours.

I did that with a black pixel on my MBP

Well, technically a stuck pixel can be black or white as well. I left that for simplicity, but the main difference between the two is that a stuck pixel has one or more subpixels stuck in one voltage state (r, g, b, on, or off) while a dead pixel is actually dead and no amount of voltage will turn it on.

If the pixel is just stuck off it can be fixed but usually a black pixel is dead.

[q=Little Blue]The DTP one has a function where it can make the screen a uniform colour, and for the three main colours and white, this pixel is visible, and it can't be seen at all on a black background, so I'm guessing its a dead one not a stuck one.[/q]

The fact that you can see colour behind the pixel suggests that it is on and not dead. Keep in mind that if a pixel is stuck on red, for example, and the blue subpixel is turned on, it will have the same effect as writing on a piece of red paper with a blue pen - the pixel will appear black. It's definitely worth a try to fix it, but as I said earlier it can take forever, or not work at all. Can't hurt to check the manufacturer's dead pixel policy.