Box containing handset icon is gray and not green?

Sometimes I see this box grayed on my Z30 for an iOS BBM contact although their status is listed as " available ". Some here have said that it just means they are not in a Wi-Fi zone so Wi-Fi calling will not work. Others say it means their iPhone is turned off and others say they just do not have BBM running ( unlike BlackBerry phones where you cannot shut BBM down) but why are they listed as "available " status if their phone is off or BBM not running?
Then there is the matter of the lingering gray check mark, instead of a blue "D", beside the message although they are listed as "available" ( so how could they have their phone off or BBM shut down, if they are "available "?).
Truthfully, although they seem to like the cool features like HD pics, retractable messages etc. , I almost regret encouraging them to use BBM as it is such a pain to deal with these sort of mysterious things on my BlackBerry end. Plus this apparent need for them to have " banner notification " on to even know that I sent a message ( unless they are sometimes ignoring my messages on purpose-- lol)

BB, Still the One

OK so to go through your comment:

- Gray box for phone icon
If they are not currently running BBM, it will be gray. Means you cannot connect to them on a BBM Voice call

- Available status
This is something that they can set - it doesn't change if the device is off, or if BBM is not running. You have to manually change this yourself, and the default is to available. You can create custom settings, and even show a busy icon, but they have to do it themselves. This goes for any BBM user

- Gray check mark
If BBM is off, it has been delivered to the server but not the device. This will happen to any Android or BB10 devices if they are off or BBM is not running for some reason

- Banner notification
They can have banner notifications, or alerts, but banners are must last obtrusive and dismiss themselves after a few seconds, alerts just stay on the screen until you manually dismiss them. They may turn them off completely and well, I guess that just sucks for anyone trying to message them!