matplotlib/matplotlib — pull request #1178 by jenshnielsen (2012-08-31 07:37:55+00:00)
Title: Make colorbar draw edge with facecolor around the faces. 

This was changed when #901 and was merged, to allow different edgecolors,
due to the way get_edgecolors behave. This restores the
original behavior of colorbar in both mpl and the axisgrid1 toolkit by setting the edgecolor to 'face'

Without the edge color set to facecolor the colorbars have white stripes in pdf. See the attached files for an example. The rendering in pdf might be viewer dependent. The png screenshots illustrates the rendering in evince on linux

Pdf before fix
http://ubuntuone.com/7YrairHdLJAaskzIC215KI
Pdf after fix
http://ubuntuone.com/1qNZvSFlXzZNRDqMAafxBJ

Screenshot before
http://ubuntuone.com/3RRIM3P6j3rqgLnXpTI2c1
Screenshot after
http://ubuntuone.com/5Dd7x4gwRXAWyPswZRfOdk