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