By default open contours are now rendered in a darkish red color.

When you complete a contour by joining back to the starting point then
that path is rendered in a normal color. Advanced users can turn off
this functionality by turning "Off" the preference
Editing/DrawOpenContoursWithHighlight.
Merge pull request #278 from monkeyiq/2013jan/issues/242

By default open contours are now rendered in a darkish red color.