Question: If the owner of a set of Chinese lay Buddhist robes, one black (海青) and the other brown (缦衣) had passed away, how should they be handled?
Answer: Perhaps the temple through which refuge and precepts were taken can be enquired, to see if it is willing to take them in, as cleaned and reusable donated items for others. They can also be kept and reused personally, kept at the shrine as a reminder to practise the Dharma, to dedicate merits to the deceased.
The brown robe especially, which is considered a Dharma robe (法衣) that represents commitment to the Dharma should not be destroyed. If no one is willing to receive it at all, the absolute last resort is to burn it, (with the black robe too, if also unwanted), in a clean container respectfully, in the midst of sincere Buddhist chanting, before returning the ashes to nature.