Unable to change the color of arrow from default red color Highlighted in below.
@startuml
robust "Web Browser" as WB
concise "Web User" as WU
WB is Initializing
WU is Absent
@WB
0 is idle
+200 is Processing
+100 is Waiting
WB@0 <-> @50 : {50 ms lag}
@WU
0 is Waiting
+500 is ok
@200 <-> @+150 : {150 ms}
@enduml