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