Can one "style" .puml files?

[mmoser18]

I am now (almost - see different issue) there to automatically create the dependency graph(s) for our project. I am creating .puml files.

One issue that remains is, that the dotted connections (test dependencies) use a gray that so light that these connections are almost invisible when printed. Is there some mechanism or option to "style" these diagrams a bit so I could define a slightly darker color?