on the checkout page, the code that passes the name is:
$WA_PP_ECO_Do_itemized[0][$nextIndex] = "Name" . strval($cartIndex+1) . "";
$WA_PP_ECO_Do_itemized[1][$nextIndex] = "".$eCart1->DisplayInfo("Name") ."";
you can edit that to concatenate other columns:
$WA_PP_ECO_Do_itemized[0][$nextIndex] = "Name" . strval($cartIndex+1) . "";
$WA_PP_ECO_Do_itemized[1][$nextIndex] = "".$eCart1->DisplayInfo("Name") ." Color: ".$eCart1->DisplayInfo("Color")."";