Provide each student with several sheets of colored construction paper cut into small pieces. Place all the pieces of paper into a hat, and have the students take turns drawing a piece of colored paper from the hat. When a color is drawn, have the student find an object in the classroom that is the same color as the piece of paper. You can create a more difficult version of the game by cutting out shapes from the construction paper, and have students find corresponding shapes in the same color.
Add a colorful twist to the "I Spy" game to teach students to distinguish color. Say to them, "I spy with my little eye, something that is green." Have the students take turns trying to guess the object that you are looking at, using the color as a clue. The student who guesses correctly can then "spy" an object of his own, using the color to describe the object to his classmates.
Place a big bag of different colored pom poms out for the students. Ask them to sort the pom poms by colors, placing each color into a separate container. Then, ask the students to name the color in each container. For a variation on this activity, cut out colored construction paper squares to match the colors of the pom poms. Have students sort the pom poms again, this time placing them on the matching construction paper squares.
You can further develop your students' knowledge by talking about colors and pointing colors out to your class throughout the day. Use colors to describe things in the room, illustrations in a book, or pictures that a student is coloring. Point out colors that you notice in the classroom or on the students' clothes. Say things such as, "I like your green shirt," or "Please sit on the red carpet," to reiterate colors to the students.