Paint tool uses the correct contour color
Summary: Set the brush color to the active label color
Test Plan: manual brush drawing with multiple labels
Reviewers: floca, O1 MITK Reviewer Group I, kislinsk
Reviewed By: floca, O1 MITK Reviewer Group I
Subscribers: kislinsk, kalali, floca
Maniphest Tasks: T28984
Differential Revision: https://phabricator.mitk.org/D606