OK guys - bear with me. I did this little test using 1/16" red fiber optic. Granted it isn't the same size as that used on the front sight but you will get the idea. I cut 2 pieces of equal length and taped them to a paint stick. One end of one optic was dabbed with white fingernail polish. (the left one).
Here are the pic. Pardon the clarity, but it still shows the effect.
Pic 1: Under normal light, polish on end of left optic.

Same angle with lower light.

Pic 3 - LED flashlight overhead. Notice how the left one with the polish on virtually disappears.

Last pic. polish easily scrapped off with thumb nail and edge of knife.

Sorry about the last one being blurry. But this simple test is enough for me to try it on my sight next time out. My worry was that the acetone in the polish would damage the optic. But it doesn't appear to be the case. The polish adhered well but came off with a bit of scraping. The end showed no sign of discoloration. And the polish did dramatically decrease the glow of the optic.

Perhaps touch the site with some White Out correction fluid... Good test. I have a hard time in bright sun with that fiber optic. It seems to get fuzzy and grow and makes a fine sight, almost impossible.

Good idea Dave. The white out wouldn't be as harsh and along toward evening on a hunt, you coul just pick it off the fiber optic if you wanted to. And/or after a shooting session, it would probably wash off during cleaning.

I dont like the red optic on anything and everything I have is red
When I shoot targets most of them seem to have red bulls eyes and I dont like green in the woods
I like blue light.