You can simply upload your preset's .fhp in the User Panel to let others see it, if that's what you mean. I'm slightly confused here, to be honest on what you're saying...
Turn it off? You'd probably just have to take off the preset for the time being if you want to do that. However, you wouldn't appear bleach-white with it on; People who haven't downloaded your preset would just see your character's default markings and colors on, so it can be hard sometimes to tell the difference between someone with a preset and not, to be honest...
Hope this helped somewhat?