A white screen is used to identify the dead pixel that is not visible on the screen. It can be caused by dust, dirt, or other objects that are blocking the view of the pixel.
Dead pixels, black dots or stuck pixels are byproducts of the manufacturing process, and they can appear on LCD screens in electronic devices. Sometimes these "defects" might not be visible on the screen at all (especially if they're white or black). Therefore, it is necessary to use totally white background in order to detect them.
Try this white screen on https://white-display.stackblitz.io/ OR https://whitescreen.website/
