When your cell is inside a colony, I think the Abilities Bar should feature a tip on how to unbind.
It could be as simple as changing the button icon as I show in the picture below.
Edit: I am now realising it would be better to show an additional square entirely, as when bound you do have both options - binding again or unbinding.
Actually, most of the times an SVG file is good enough. So you can hit me up with that, depending on whether the art team wants and needs help or they don’t.