In discussion with our Chief Apostle, the following direction has been decided: 
As of October 2, 2017 (the day after our Church Thanksgiving), black and white will no longer be required by our choirs, except for Church holy days and festive occasions.

Church holy days are Christmas, Palm Sunday, Good Friday, Easter, Ascension, and Pentecost.  Festive occasions are Church Thanksgiving, (3) Service for the Departed, Funerals, and scheduled Chief Apostle and Apostle visits.  It may happen that the Apostle or I make a visit to the congregation unannounced and we realize the choir will be as they normally are.

From time to time the local choirs may opt to mark the occasion with a special accessory to their dress (i.e. a coloured scarf or tie for Christmas).  We have seen this in our concert choirs.  I have no objection to this as long as it is not a financial burden to our choir members.

This is a general guideline going forward.  It can happen that someone shows up no dressed according to the occasion; please do not bar them from singing.  Our goal is to remain inclusive and promote that all our members use their gifts in the service of our triune God.

from a District Apostle Woll letter date July 26, 2017