Graham has provide a solution that works for you. However, to your stated requirement "bulleted" text, the following minor modification will limit processing only to those type paragraphs:
Code:
Sub ScratchMacro()
'A basic Word Macro modified by Gregory K. Maxey
Dim oRng As Range
Dim oPara As Paragraph
For Each oPara In ActiveDocument.Paragraphs
If oPara.Range.ListFormat.ListType = wdListBullet Then
If oPara.Range.Font.ColorIndex = wdAuto Then
oPara.Range.HighlightColorIndex = wdYellow
End If
End If
Next oPara
lbl_Exit:
Exit Sub
End Sub