In my top screen for my Ds there is a piece of dust inside or it looks like a piece of dust. When I turn it on the spot that it is in becomes a dot that changes color as I rotate it. It changes colors to blue, red and black. Is this a dead pixel?
A single grey/black dot is a dead pixel. A coloured dot that does not change is a stuck pixel (can somtimes be fixed with flashing different colours on the screen for a long time) However your saying it changes colour so my guess is that it is something that is breaking up the background light so you see a different colour depending what angle you look at it, so chances are it is a bit of dust or similar.
