I made this really simple matching game with just a few index cards and some colored cardstock. Your child matches the colored square to the card with the correct color word.
Using this with my elementary aged son, we used it as is, so he could practice recognizing them as sight words. With a younger child, you can easily adapt this activity by writing the color word in its color (write blue in blue). This would make it easier to make a match, but would still allow the child to become familiar with the word.