"Name that color" Concentration and Impulsivity Test

The easy practice test:
Read the colors aloud (not the meaning of the words).
To time your response, click "Start" when you are ready to begin; click "Finish" when you are done.

RED YELLOW BLUE GREEN BLACK PINK ORANGE BROWN GRAY PURPLE GREEN RED BLACK BLUE YELLOW PURPLE GRAY PINK ORANGE BROWN

Elapsed time: sec

It is easy because the color and the word are congruent.

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The real hard test:
Read the colors aloud (not the meaning of the words).
Note that it is the same list of words but written in different color.

PAY ATTENTION: The color of the words are different from what the word says.
To time your response, click "Start" when you are ready to begin; click "Finish" when you are done.

RED YELLOW BLUE GREEN BLACK PINK ORANGE BROWN GRAY PURPLE GREEN RED BLACK BLUE YELLOW PURPLE GRAY PINK ORANGE BROWN

Elapsed time: sec

Do you notice it takes twice the amount of the time to complete the second test?
The above demonstration does not even take into account the incorrect responses in naming the colors.
The reaction time will increase with fatigue and/or inattention to the task, so if you retake the test, it will show slightly different reaction times and error rates.