blue pixel

Hi I see on my window setting that I can go up to 75hz? Now I see some stuck pixel? Does this have any connection at all? My display box say's 60hz and I see 75hz and I set to that settings. Does it cause something? Or problem I may encounter for using 75hz on 60hz display

Good day everyone =) I recently have an issue with my laptop's screen. View: https://imgur.com/a/JAWAXCN As you can see in the images, there is a bluish stain in my screen, but the best part is that is only visible on dark images or black screen. It cannot be visualized unless the screen has...