It looks a bit like the acro that I call a "blue smurf" but in my frag system it's usually a purple-ish color. I'm 95% sure that I gave you one to try out because it's pretty hardy and grows really well. However, I've never seen it that color or even really close to that color. That isn't necessarily a surprise since I have seen it several different colors but I'm not certain that's what it is. Any chance you remember it being a darker and more purple color in the past?