You can play with this...
_Word_Color_Text(@ScriptDir & "test.doc", "This text should be blue", 0xFF0000)
; Find text and change it's color
Func _Word_Color_Text($doc, $str, $color) ; document path or object, text to find, color
If IsObj($doc) Then
$oDoc = $doc
Else
$oWord = ObjCreate("Word.Application")
$oDoc = $oWord.Documents.Open($doc)
EndIf
$oRange = $oDoc.Content ; select entire document
$oRange.Find.ClearFormatting() ; clear previous search
If $oRange.Find.Execute($str) = True Then
; $oRange.Bold = True
$oRange.Font.Color = $color
EndIf
$oRange = 0
If Not IsObj($doc) Then
$oDoc.Save
$oWord.Application.Quit
$oWord = 0
EndIf
$oDoc = 0
EndFunc
Edit: It's a quick mod of a function to make text bold. It accepts either an object to an already open document (in which case it leaves the document open), or a string filename (in which case it starts Word, opens the document, makes the changes, saves the document, and kills Word).