You can now, not sure if that was available at the time (in the volume sensible for a green room): https://www.mms.com/en-us/shop/single-color
Amusingly the UK version does not offer brown ones.
Amusingly the UK version does not offer brown ones.
Did latex gloves not exist in the 80s?
Actually, come to think of it, it's possible one could simply order pre-sorted M&Ms directly from the factory if one were buying in enough bulk.