Group Line Color

All of a sudden the line color on grouped objects on my CorelDraw 2017 has changed to blue, and I can't find how to change it back. It worries me because I'm drawing plans for laser cutting and line color matters. What did I do to turn this feature on and what do I do to turn it off? I've searched all the preferences and don't find anything and searched the Corel help site with no luck either.