Do you notice it takes much longer time to complete the second test than the first test?
The first test is easy because the color and meaning of the word are congruent. There is no conflict.
The second test is hard because the color and meaning of the word are incongruent. This creates a conflict that the brain has to resolve
The reason why it takes longer is because the brain has to suppress the wrong answer that interferes with the right answer, before the right answer comes through.