So, what's the point? Do not read the word but say the colour in which it is printed out loud. Increase speed. Do it criss-cross. Find out how awfully difficult it is. Something to do with your brain halves, I think. What if you have only got half a brain?
Does not work if English is not your native language.
Does not work when you cannot read (guffaw).
YELLOW BLUE ORANGE
BLACK RED GREEN
PURPLE YELLOW RED
ORANGE GREEN BLACK
BLUE RED PURPLE
GREEN BLUE ORANGE