Use some acetone to try and dissolve colour away. If you are successful, throw the piece away. If the glass is coloured not painted, it should merely clean it and then it's all good.
Paint won't necessarily mean lead, but is undesirable nonetheless.
A lead painted rig isn't as bad as it sounds too, it's just important to avoid cross contamination with food or other items. It won't vaporize off the piece, it shouldn't absorb through skin. As long as you wash your hands after handling it, it's fine. If the paint is internal or is a part of the vapour path, it's not innately dangerous but it is even less desirable.
For the most part, lead risk from china glass is overblown. Glass itself isn't healthy if you eat it, but that's a very uncommon practice. Lead boils at over 2000 K, don't believe the hype