These are my favorite and standard sights I use on my pistols.
In addition to the obvious benefits in the dark of the illuminated trituim dots, the coloring helps immensly in dawn and dusk lighting where the tritium isn't glowing yet. Also the shape obscures less of the target. I use these exclusively in 3-Gun and Steel Challenge pistol matches.
My experienced opinion is that upgraded illuminated sights are a much better option for a pistol than a laser, because when using a laser your "gunmanship" will get sloppy and it's just too easy to jerk a pistol off target.
I have also experimented with many weapons lasers, on carbines and shotguns. Green is far better than red in my opinion. It is far easier to see and has greater useable range. Know that all lasers lose output power significantly as the temp drops, and I have found that US legal 5mW units of either color are basically useless around 30 degrees and even the 110mW imported units are dead by 10 degrees.
Another option you may not have considered, is a weapon light. The Streamlight TLR-1s for instance puts out a blinding 160 lumens, has a strobe function, and the spot is so precisely centered it can be used for aiming either at pistol or shotgun ranges. $105 on Amazon.
SENTINEL - SGT USMC
I second the sarge's opinion.
I put lasers on a few of my long guns and pistols and have removed all of them. Weapon lights are much better and if you do not want to use the light then use night sights, again like the sarge said.
I found I was sometimes pulling my shots with the lasers and using lights and night sights brought my accuracy back.
If you must have a laser take into consideration that while the green can be seen much better in the daylight it makes a perfectly straight line back to you at night. Not so much with the red. Also, how many hip shots will you be using during the day? Much better to draw the gun up and use the sights. If you are moving you aren't going to get a proper bead on the target even with a laser.
In my opinion, laser sights for a pistol, scope for a rifle. Red is fine for most handgun situations, which tend to be close-combat and either inside or outside in the dark or twilight.
They mentioned the temperature issue in the article I mentioned – but only in context of the green – but the same physics would certainly have an adverse effect on both.
Part of my interest in the subject matter has to do with laser sight/light combos – so that’s an interesting idea.