@startuml skinparam backgroundColor #EEEBDC skinparam sequenceArrowColor DeepSkyBlue skinparam sequenceParticipantBorderColor DeepSkyBlue skinparam sequenceActorBorderColor DeepSkyBlue skinparam sequenceLifeLineBorderColor blue actor User participant "First Class" as A participant "Second Class" as B participant "Last Class" as C User -> A: DoWork activate A @enduml