Better colored shrimp will have better coloration than lower grades, regardless of color of the substrate.
Generally speaking, females will have 12-30 eggs. It takes approximately 3-4 weeks for the eggs to hatch.
You might be able to encourage breeding by feeding a high protein diet (too much protein isn't good!), such as frozen blood worms or brine shrimp, or having a sudden temperature drop in the tank (but not too drastic!) via a partial water change. Care needs to be taken though, as it is possible to cause a berried female to molt, which means she'll shed her eggs with the molt.
Females mate shortly after molting. Males will mate with any available female that's willing.