Purple and blueish pixels on screen

So I've bought an MacBook Pro (Retina, 15-inch, Late 2013) in the beginning of the last year (2014).

After more than one year of use I started to notice some random sparkles-like pixels on the screen. Generally with purple and blue colors. They only appear in darker colors (dark blue, dark grey, dark purple, etc).

Its like that when the screen must turn darker they go full rebel and don't obey like other pixels.

I have no idea what it is and no idea how to fix it. Anyone had experienced anything closer to that?

(OBS.: THE STRAIGHT VERTICAL LINE ON THE PICS BELLOW IS FROM THE SOFTWARE, NOT A SCREEN PROBLEM)