How to change the default color choices

[Stephan De Spiegeleire]

Right now, when we run co-terms analyses, the graph shows up with the following coloring scheme. . As you can tell, the yellow cluster labels are barely legible. We can of course always change these manually, and we can use one of the predefined styles. But Is it possible to change the defaults values? The same also for the edges (which now by default get 0.2 transparency and are also barely visible), for the tree rings (we'd rather not show them initially), etc.
Thanks!

[Chaomei Chen]

I'm posting a new version 6.1.R2 Built 6/20/2022. Cluster labels should be more readable. See attached for example.