Colors

List the colors with:

@startuml
colors
@enduml

Which gives something like this:

Change the color of all objects of a particular type, use skinparam for the type, example:

@startuml
skinparam artifact {
	BorderColor black
	BackgroundColor lightskyblue
}
artifact "software project" as softproj
artifact "infrastructure config" as infra
@enduml

Change the color of a single item, specify color at end after a hash. Example:

@startuml
artifact "software project" as softproj #darkkhaki
@enduml