Project 2010 Gantt Bar Edit error

I am writing some Project 2010 VBA, and I have a section that deals with Gantt Bar settings. I run into an "Arugment is not valid" error at this line when running my module:

Application.GanttBarStyleEdit Item:="Task", From:="Start", To:="Finish", MiddleColor:=pjMaroon, MiddlePattern:=pjMediumFillPattern, LeftText:="Start", RightText:="Finish"
   

All of that should be valid. So, why is there an error?