from matplotlib import pyplot as plt
from matplotlib_venn import venn2
from collections import OrderedDict

named_sets = {'x1': set(['foo','foo','bar',"pax"]), "x3" : set(['foo','qux','bar',"zoo"])}
od = OrderedDict(sorted(named_sets.iteritems()))

circlenm = ()
circlels = []
for k,v in od.iteritems():
    circlenm = circlenm + (k,)
    circlels.append(v)


c = venn2(subsets = circlels,set_labels = circlenm)
c.get_patch_by_id('10').set_color('red')
c.get_patch_by_id('01').set_color('blue')
c.get_patch_by_id('10').set_edgecolor('none')
c.get_patch_by_id('01').set_edgecolor('none')
c.get_patch_by_id('10').set_alpha(0.4)
c.get_patch_by_id('01').set_alpha(0.4)
plt.show()