Try the following
Code:
Sub MakeBlack()
Selection.Find.ClearFormatting
Selection.Find.Replacement.ClearFormatting
Selection.Find.Replacement.Font.Color = wdColorBlack
With Selection.Find
.Text = "*"
.Replacement.Text = "^&"
.Forward = True
.Wrap = wdFindContinue
.Format = True
.MatchWildcards = True
End With
Selection.Find.Execute Replace:=wdReplaceAll
End Sub