Hello N.,
Because when a component becomes a rectangle... it is necessary to change rectangle skinparam! 
Here is a workaround:
@startuml
skinparam component {
style rectangle
}
skinparam rectangle {
BorderColor Orange
BackgroundColor Red
BackgroundColor<<static lib>> Blue
BackgroundColor<<daemon>> Green
}
[R]
[B] <<static lib>>
[G] <<daemon>>
@enduml

If that can help,
Regards,
Th.