Like Sura said, if others see you white, then you must be wearing a custom markings pack. But if you are using the default markings, but you are wearing a preset, then others can only see your default markings. If you put your preset download link in your bio or on this site in the Presets and Markings section, then people can download it to see you in game.
However, if you are not using the default markings and are wearing a preset, and others don't have your marking pack, then you will come out as white. Make sense?