Hello Rick & All,
> For two winters I placed black felt paper around 50 hives and left 50
hives
> with plain white exteriors, results, it made no difference.

Perhaps not in your area. Most beekeepers do not wrap in our area. Those
north of me which do swear by wrapping.
Many do not realise hives are wrapped to prevent rapid changes in
temperature inside the hive. When the temperature drops fast bees can get
cought away from the cluster. In northern areas (Canada) temps can drop
20-30 degrees in short order. Also tests show that bees move around in
wrapped hives at lower temperatures than unwrapped hives. They also use less
stores in the articles I have read. I do not wrap hives in Missouri but
wouldn't of mind having the hives wrapped last November and December. We had
the second coldest Nov. & Dec. in weather recording history.
Bob