Could it be added? Maybe technically, however it would be largely ineffective IMO and kind of look a little funny. You can of course try and simulate this with Testor's Gold colored paint. Paint a dot to replicate what you want and test fire the revolvers.

I have a few gold colored inserts on Rifles and they are very hard for me to see - especially once they get covered with a little carbon and gunpowder residue. IMHO you would be better off with paint as it is much shinier and brighter. The good news is you can experiment with different Testor colors until you het to the right one for you. They make all different ones throughout their extensive line of colors and I'd bet some of hem would help you out. There is a color chart online or better yet, if you can get to a Michaels, Hobby Lobby, or other similar Craft store they=n you can look at them in person. They normally sell for about $2.50 - $3.00 a bottle so you can try a bunch without wasting a lot of money.

By doing the above experiments you can sort of find out where you would stand with no alterations to the revolvers. For what it is worth, I stopped dovetailing the front sights to accept the plastic inserts many many years ago and now just use testor's paint - IMHO it also works much better.

I also agree that the fiber optic sight might work well, but look a bit funky.

Oh - and let me just add this...... Painted sights, gold beads, etc. look very different when used in different lighting conditions. While some colors work well indoors, they totally wash out for me outside in the suns light, so before drilling, cutting or modifying, try and test the color out in several lighting conditions. Just another reason to use the paint - it can easily be altered with no damage or hassle.