In pitch-darkness, a large front sight with both itself and the rib of the barrel coated with luminous paint is useful, provided the pistol is, for several hours previous to being used, exposed to strong sunlight. If it is kept all day in a case or holster, the paint will not shine at night. Also, in cleaning the pistol, the paint may be spoilt and may require renewing. I would not advise painting any pistol you care about.
The most satisfactory way is to learn to shoot in the dark by the sense of direction, by pointing your pistol in the direction in which you conjecture the object to be, not attempting to see your sights or to “draw a bead.”
One can often see an animal on a very dark night by crouching down and getting it against the sky-line; and yet, on looking through the sights, you cannot discern anything.
One form of practice is to have a target made of tissue paper, with a candle behind it to illuminate it. The sights are consequently seen in silhouette against it. This was the principle of the “Owl” series of prizes shot for in the early days of Wimbledon in the evenings. What I think better, so as to teach shooting by sense of direction, is to have one or more metal targets about a foot square hung by wires (these will give out a ringing sound when struck, and the rest of the butt should be of sand, or sods, or wood, so as to make a different sound). Have a small sleigh-bell hung behind the middle of each target, operated by strings held by an assistant standing behind you.
Now, let him ring the bells at random, you firing by sense of direction towards where you hear each bell ring.
This practice can also be done in a shooting-gallery at night with all the lights turned down, and it is perhaps safer there than out-of-doors.
You can even have targets behind you, and swing round and “snap” at them; but this, and in fact all night shooting, is very dangerous, unless you can be absolutely certain that the bullets will do no damage, however wildly they may fly.
A man with a good ear can do surprisingly accurate work in this style of shooting.
Such practice can be done in daylight by being blindfolded; and then your assistant can notice where your misses go, and help you to improve your shooting.