Completions Buttons

One minor change I would like to see is the potential to customize completion buttons to have more options than just "complete" or "incomplete".  For us, I could see a use in "Not Applicable" option.  For example, our list of completions include items like "Event Pre Check", "Catering Check", and "Event Post Check".  Regardless of the event, we always do a Pre Check and a Post Check.  However, some events have catering and others do not.  I would love to be able to check off "catering check" in a different color (maybe yellow or gray) that would designate an item that is not applicable or not required for this event.  The green color tells me that the item has already been done, but I don't really want to check that since it actually hasn't.  In contrast, the red button cues me that something still needs to be done when in reality no action may be required.  Do others have similar scenarios with a work around?