Dead pixel with but with inverted color in rMBP I have a mac book pro retina since a few weeks (bought in april 2013). There is a pixel in the middle of the screen that has the opposite color of what it should have:


If background is white, pixel is black
If background is black, pixel is white


So it's not technically a dead pixel, but similar. (just more annoying because it see it on black backgrounds...)

How can I diagnose if this is a software or hardware problem ? Are there any standard test that I can run ?
Dead pixels aren't necessarily "black pixels". Although it's common that the dead pixel stays black, they also come in different colors and, as in your case, they can change colors too.

The way to tell if it's a software problem is to check if the pixel appears dead right after turning on the machine. If that is the case, it must be a hardware problem because the software has not been loaded yet at this point.

Check this, and if it's a hardware problem, my guess is a failing graphics card or display. Time to take it to an Apple Store :(