Set up your buttons, then get rid of the UIButton or UIButtonColor script on them, and add a UICheckbox instead. Duplicate the button's background (bring its depth forward), bring the label forward more, and change the duplicate background's color to whatever you want it to be when it's highlighted. Now on the checkbox script, specify the checkmark to be this duplicate background you created. Last but not least, set the radioButtonRoot on UICheckbox to be the parent object that all your buttons are parented to.