Read the names of these colors and record your time.
RED BLUE GREEN BLACK
Now, read the ‘names’ of the colors in which they are written, not the word themselves.
GREEN PINK BLUE BLACK
You will see that even you find it difficult to say the second set of words out faster than the first set. Ask your kids to do it, until they get it right. Increase the number of words and colors as you wish to make it more challenging.