Revert "Merge branch 'colormap-chosen-field'"

This reverts commit 7f33fed440a4f68fe6b16de08ee01a5935addfbf, reversing
changes made to 630a52f7dbeff144b4cd22e84652dac8885131c7.
Revert "Merge pull request #73 from Kitware/fix-merge-conflict"

This reverts commit 497a2616d98511a3065e8278765ed0ef2463b2b0, reversing
changes made to 7f33fed440a4f68fe6b16de08ee01a5935addfbf.