No, dead pixels look like any other pixel when the screen is off, they just don't get power (like the other pixels) when the computer is on. Odds are you have some dust, or some sort of residue perhaps, on your screen.
Funny thing is, it appears to be underneath the surface.
It's either new or I haven't noticed it before. I only noticed it because I cleaned the screen today, I thought I might have pressed too hard and caused a dead pixel. But I can definately see it if I shine a light on my screen when it is turned off.
Strange.
if you're sure you don't feel it on the surface it is a speck of dust or some impurity between the screen and the glass,nothing you can do and be happy you don't really notice it