This example uses the RGB function to set the slide master background color for the new presentation to salmon pink, and then applies the third color scheme to the new presentation.
Private Sub App_NewPresentation(ByVal Pres As Presentation)
With Pres
Set CS3 = .ColorSchemes(3)
CS3.Colors(ppBackground).RGB = RGB(240, 115, 100)
.SlideMaster.ColorScheme = CS3
End With
End Sub