Yeah, well it works in fish to make them redder. In neos it tends to overly work by bringing out blue and then changing to brown. Not only on pigment, but tissue too. So it has a different effect. I'm told it doesn't have that effect in crs though.
But if you don't believe me, it's easy to try yourself by giving your neo shrimp astaxanthin powder for a month and see what happens. I kept a journal when I did my experiment, because there was differing information on the web..