In several embodiments {HEAD ~ different areas} of the film have {TAIL ~ different thicknesses} for producing different interference colors 
In several embodiments { HEAD ~ different areas } of the film have { TAIL ~ different thicknesses } for producing different interference colors
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH