http://news.yahoo.com/s/ap/20101130/ap_on_fe_st/us_odd_red_bees_mystery (http://news.yahoo.com/s/ap/20101130/ap_on_fe_st/us_odd_red_bees_mystery)
Either it is from the cherry juice, or someone has humming bird feeders close by.
That's pretty interesting that the bees themselves would turn red.
I did a cutout last summer. The hive was loaded with red nectar/honey. It was the color of automobile transmission fluid. Very weird!