In case you need to change the grout of an existing pattern (without applying it again), you can click the right mouse button over the pattern, and select the command Change grout.
Remember to specify the new grout value in coherence with the unit measure you formerly selected in the Application preferences. If you do not remember it, look at the status bar, bottom right side of the Application window.
This article is valid for DomuS3D® 2017 and later versions