The answer is DOLLAR BILL
The corresponding square is house puzzle
   by Kiran Kedlaya


solution:
Each picture is of an object of one color whose name indicates a different
color. Each color must be identified with one of the ten colors used to
color-code electrical resistors: from 0 through 9, these are
   black, brown, red, orange, yellow, green, blue, violet, gray, white

Here are the intended identifications:

   Yellow Cab, actually orange
   greyhound, actually black
   Green Building, actually gray
   black box, actually orange
   Greenland, actually white
   green card, actually red (pink) (and violet will work as well)
   blackboard, actually green
   Brownie camera, actually black
   Red Sea, actually blue
   white wine, actually yellow
   blueberries, actually purple


Code each pair of colors as a pair of digits and use them as lookups into
the table at the top. One way, you get
   PAT DAY HORSE
and the other way you get
   BACK IS GREEN

Pat Day is the jockey who this past year rode DOLLAR BILL at the big
three races, but didn't fare as well as he was supposed to (an early
favorite for the Triple Crown, actually).  Plus, a DOLLAR BILL or
greenback is mostly black on the front, but yes, all green on the
back.