Geoff,
If you are only interested in the main text part of your document then
something like this will do:
Sub Scratchmacro()
Dim oRng As Word.Range
Set oRng = ActiveDocument.Range
With oRng.Find
.Font.Color = wdColorGreen
.Replacement.Font.Color = wdColorBlue
.Execute Replace:=wdReplaceAll
End With
End Sub
If you are talking about "all" parts of the document e.g., headers,
foorters, textboxes, etc. then you will need a more complext macro that
process all the story ranges of the document. See:
http://word.mvps.org/faqs/customization/ReplaceAnywhere.htm
Also note that in Word2007 what may appear to be font wdColorGreen actually
has a specific theme color number (I guess that is correct). To find what
this number is, you will need to select a bit of the Green text and run this
code in the the VBE immediate window:
?Selection.Font.Color
The number returned can be used in place of wdColorGreen in the code above.