Sets the GRUB graphical screen mode used by themes and the graphical terminal. The theme provides layout and images, but this setting chooses the resolution GRUB renders them at.

Use auto to let GRUB choose, or enter one or more modes such as 1024x768 or 1280x1024x32, separated by commas. If a theme is cropped or shifted, try a resolution closer to the one the theme was designed for.