You can get blue fiber and it is being used on the target circuit but the ones I looked at didn't seem that bright to me but a blue light on a green pin is awesome.
I don't like lights or real bright pins in low light.They take over the sight picture and make it very hard to see where you are trying to aim.
I have shot many night shoots and have won more than my fare share and people are always surprised that I use no lights and want no one to shine a light on my pins.I just cast a shadow,or rather just look through the dark pin and can see what I am aiming atmuch better.
Just added food for thought.