How to look for empty cells in a range using vb?

Replace it all:

Sub look_for_empty()
ActiveSheet.UsedRange.SpecialCells(xlCellTypeBlanks).EntireRow.Font.ColorIndex = 4
End Sub

Although if your code didn't work that probably won't either, are you sure they are blank and not a space or something? An example workbook might be helpful in this case.