I was experimenting with a custom skin. Applying this in a sequence diagram works fine, but I don't seem to be able to use it for other diagram types. Is this syntax different for other diagrams or is it just not implement?
' this one works
@startuml
skin BlueModern
a -> b
@enduml
' this results in a syntax error
@startuml
skin BlueModern
class a
@enduml