I keep Spotted Blue Eyes (Gertrudes) and they are wonderful fish for a 10g. You could easily do 12 but be sure to at least have an even number of male to female or have slightly more females. They enjoy some floating cover and it's not too hard to get them to spawn if you have floating plants with longer dangling roots such as water lettuce or water hyacinth or have a large area of some type of moss. Mine has spawned the day after a WC with slightly cooler water. Usually it happens first thing in the morning. Also since they utilize the upper water level you can keep something like Burmese Rosy Loaches or Multi Striped Pygmy Loaches for bottom activity as they are both very tiny. Here's a pic of one of my male and female Rosy Loaches. The female has the spots/broken bars. Over time the males get quite a nice salmon red color...
Aquarium Advice - Aquarium Forum Community - Rivercats's Album: 55g Planted- Nano fish - Picture. Or you could do some small shrimp. I have Fire Red Cherry Shrimp which are a really incredible bright red. They would make a nice addition with the Gertrudes as well.