They're Stock equipment on HK's New P30 They Glow brighter than tritium (not sure how) but must be precharged with a flashlight or other ambient light source.
And When I got one of my first newer model guns, a beretta 96, it came with common painted dot sights. I spent roughly $50 on that sight paint garbage to avoid the cost of having a gunsmith install other sights on this gun. Finally realized I'd have been $50 bucks closer to the real deal If I Had just been patient.
If thats not an option, my second choice would be HI VIZ fiber optics. They're not tritium but if you use a light in one hand and a gun in the other (Rogers/ Ayoob Technique) the light will be picked up by the sights and they'll look like they do in day light.