Color Interior If Criteria Is Met

I have some code that recently I found I had a new criteria that I originally did not have when I worked my original database. THis code works perfectly as is BUT if in column "D" if this is blank I would like to do nothing/ make no changes in that row.

Sub ChangeColorsotherdesigXXX()
Dim c As Range

For Each c In Range("D2", Range("D65536").End(xlUp))

With Range("a" & c.Row & ":s" & c.Row)
If Not CStr(c.Value) Like "612#" And Not CStr(c.Value) Like "712#" Then
.Interior.ColorIndex = 36
.Font.ColorIndex = 1
End If

End With
Next

End Sub