Rainbow Art:

    Let the kids choose crayons, colored chalk, or colored pencils to create a rainbow background.  Use whatever paper size you wish, and give directions to completely cover the page with color by using the colors of the rainbow in the correct order: red, orange, yellow, green, blue, indigo, violet.  The background design can be horizontal stripes, vertical stripes, wavy stripes, arched like a rainbow, or zig-zag stripes.  After the background design is finished, give the kids die-cut shapes from black construction paper to glue to the top of their background design.   If your school does not have a die-cut machine, then let them trace stencils of simple shapes such as hearts, balloons, stars, etc... It is a fun project.  The black shapes make a great contrast against the rainbow colors of the background, and it also looks great as bulletin board or hall display.

An Example of Rainbow Art:

Rainbow Streamers:

    Take 2 pipe cleaners and fasten them together to make a circle.  Next, give each child a streamer for each color of the rainbow.  Have them loop each circle through the circle, then glue it or tie it in place.  Be sure to attach the streamers in the order of the colors of the rainbow.  When finished, let the children dance to the music of "Hooray for the Rainbow," or any other song that is suitable. The kids really enjoyed this activity. 

An Example of the Rainbow Streamer:

Edible Rainbows:

    Use jelly beans, fruit loops, m&m's, or any other food that has the colors you need.  Have the children sort them and arrange them on their desk in the order of the rainbow.  Use them to make addition or subtraction problems.  For instance, 2 red plus 3 green equals 5, etc... The kids can also use their food to make a rainbow graph. This is fun to do after reading The M&M Counting Book.

Read to the class My Crayons Talk, by Patricia Hubbard.  Encourage the children to study the illustrations, which are nearly monochromatic, then to come up with their own design to illustrate their favorite color.  The illustrations in the book cleverly used a crayon as part of each picture. For instance, the red crayon was the post of a Stop sign, the blue crayon was a jet in the sky.  The class really enjoyed the ideas.

An Online Printable game and riddle page:  

The Rainbow Scramble!