question: What color are the two objects that share color, size, and material?
#1 return objects 
#2 return number of  #1 for each color  
#3 return #1 where #2 at least two 
#4 return number of  #3 for each material 
#5 return #3 where #4 at least two 
#6 return number of  #5 for each size 
#7 return #5 where #6 at least two 
#8 return color  of #7