RE: violet and white fiber optics
Usually these fiber optics are used in conjunction with a little blue light.This will make them visible but they really are not for hunting.
Also,using a lighter is a bad way to ball the ends of fiber optics because you do not get an even ball and one side of the fiber will transmitt more light than the other side and in different light conditions will actually cause you to see more of one side than the other and therefore causing your pin to be in a different place than where you thought.It also cause more of a halo effect.
What Ausie suggested is much better and what I do is use an iron on high.Works great and you get an even ball.