Maybe some HK style sights? As ucrt said above, the rear sight isn't something to look at but a hole to look through. The orange paint isn't a bad idea but Truglo makes a sight post for an AR that combines a fiber and Tritium. That fiber is BRIGHT and is an easy to see spot.
I'm really, really lucky with my eyesight. I need reading glasses, so I can conduct my life without anything on and only need put on some cheapo dollar store glasses to read. What this also means is that the rear sight is fuzzy and the front sight is clearer, a great help (and finally an advantage to "too short arms".).

