I would use Americolor gel in Teal to get that color.
Same as Dayti. Maybe a touch of Americolor turquoise as well, if your real life cake has a bit more blue than green.
Same as above but I have decided to call it Seafoam Blue
I would start with a small amount of Americolor sky blue. That tends to be quite greenish to me. If it's not enough, maybe a tiny amount of teal, but try it in a small amount first.
Love this color combo. It's one of my favorites right now. Love pairing it with an orangey pink made by a touch of americolor tulip red, or even a nice purple.
I agree with FrostedMoon. You can always make blue more green but making green into blue, not so much.
thank you everyone! I've had NO luck making special blue colors and it has scared me into not wanting to do such custom colors. I am coloring fondant so I will start with a very small amount and see what the best combo is. Hopefully this works ok. :P