Hey there! The loops aren't meant to actually be invisible, just undetectable to the unsuspecting eye. You're probably looking at them on your wrist right now and know they're there. If you're performing somewhere with just a little shading and your audience is a foot or two away NOBODY will see them :)
Keep in mind, direct sunlight will almost always expose the loops, like any other invisible thread product. you have to watch out for this when performing.