What is the shape of the two rubber objects which share a color?
return objects ;return #1 that are rubber ;return colors of #2 ;return number of  #2 for each #3 ;return #3 where #4 is two ;return #2 where #3 is the  same as #5 ;return shape of #6
['select', 'filter', 'project', 'group', 'comparative', 'comparative', 'project']