Your goal is to find the secret four-color code. The following colors are possible: green, yellow, brown, red, blue, black.
Some guesses have already been made. I will provide feedback for each guess made with which it is possible to unambigiously determine the secret code.

Previous Guesses:
Guess: ['yellow', 'black', 'red', 'blue']. Hint: two colors are in the secret code but in the wrong positions.
Guess: ['green', 'green', 'yellow', 'black']. Hint: three colors are in the correct positions.
Guess: ['green', 'yellow', 'yellow', 'brown']. Hint: one color is in the correct position and two colors are in the secret code but in the wrong position.
A B C D
brown, brown, yellow, green brown, green, yellow, black brown, red, green, red yellow, green, black, red