Based on the description, I would say the tiles are light blue in my case!
Button view: Displays all contacts as buttons in the Directory window. Button colors indicate the following:
White: Telephony status is unknown (for example, a personal contact with a PSTN number).
Light red: The contact's phone is in DND mode or forwarding calls to voice mail.
Light green: The contact's phone is ringing.
Light blue: The contact's phone is off-hook.
Light gray: The phone is unreachable.