Blue pixels are defective pixels but not necessarily dead. They usually result from a bad shot on the screen during a transport for example or an object that shocks it unfortunately. They can be resuscitated using software that will flash the pixel at regular intervals.
The best-known pixel flash software is Undead Pixel 2.2 which works on 40% of the screens tested. The success rate is average but it can still work.
You have to locate the pixels and then launch the flash area(s) for several hours.
– JSreenfix.com, 60% success rate, also works on mobile and TV screen.
– Deal Pixel Detect And Fix (DPDF) for Android.
There are other eccentric solutions like:
– massage the area of the screen where the dead pixels are located for several minutes,
– tap the screen with the tip of a pen (without typing with the ball full of ink of course),
These last methods may work but they can also make the problem worse and create new blocked or dead pixels. It is therefore not recommended to massage the screen. It is better to stay on a software solution. And when the software has no effect, accept that the last blocked pixels persist.
It may be that the blue pixels disappear on their own without doing anything. Just continue to go about your business (surf, game, work) and with the color variations, the pixels will soften and disappear. You will just need to no longer pay attention for a while.
If no method works, you are good to buy a new screen, or you can get used to this (these) blue(s) pixel(s).
PS: Personally, I had 800 frozen light and dark blue pixels on the screen after a move and a bad shock on the screen. And little by little they disappear thanks to the use during several hours of JScreenfix and then Undead Pixel. These methods heat the circuits where the pixels are damaged and reactivate the system that animates the pixels. Gradually, they come back to life.