acquiring, from the product information storage unit, color information on {HEAD ~ related products} that differ in color from {TAIL ~ the products} 
differ from
acquiring , from the product information storage unit , color information on { HEAD ~ related products } that differ in color from { TAIL ~ the products }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL