I see that my new XDs came with replacement fiber optic filaments red and green. I have watched the videos on how to do this, so I see how easy it is. 

 

But was wondering if any other owners changed theirs out to the green? since the human eye sees that color better.

 

 

Why do they not just install the green out of factory if its so much better?

You might be able to "see" green better but if red makes a better contrast against your target it's an easy choice.

 

Red shows up better for me. Just my personal preference.

I have tried both in my Glocks and  isee red better also. i have seen some green FO that was a lot brighter than the stuff that came with my Warren/Sevigny sights so it may depend on the FO that you have, I have also tried the green from Dawson and I didn't like that either. The red seems to gather more light.

on my MP22, i have Dawson green rear and red front..  contrast seems nice and easy enough to see..  i had the same thought initially, to change the front to green immediately, but once i shot it with the red front, i decided i didnt need to..

Same here, I see red FO better than the green.