I used to use Testors paint on my sights, then I went to nail polish. Now-a-days I prefer to not color the sights.
To me as I got older the painted sights glow and have a halo (for lack of a better word) around the sights, making them blurry, particularly the front. It makes it impossible to accurately aim the gun.
A side note, my old pistol silhouette gun (a customized XP 100 in 708 Remington) has a Lyman 17A front sight on it. A hooded front sight you can change the insert on.The width of the post or the I.D. of the ring or even a translucent orange with a clear center. I preferred the narrowest post available because at 200 meters the Ram target was none to big and I preferred to shoot the feet out from under the target to assure that it would fall, otherwise it didn't count.
What I'm trying to say is that colored sights have their own problems. Having said that, you should probably go with a dark red or bronze color.