Look at the chart below, and read aloud the color of the word.  Don't actually read the text.  If you see BLUE, say "red", not "blue".  It's amazing how many people screw this up.  The chart is randomly composed of six colors:  red, yellow, green, blue, purple, and black.  It really works better if you read it out loud.  Click here or press Refresh to recalculate the chart.

It is difficult because the right side of your brain tries to say the color, but the left side insists on reading the word.  We're just too used to reading a word as soon as we see it.  Don't feel bad if you screw it up repeatedly.

Did you have loads of fun?  Perhaps you're daring enough to try the challengingly exhausting Stroop Marathon (it may take a while to load).