Went to Hoffman site and it is great! I can use this simple but powerful
activity to really show how colors advance and recede. I can also use it to
have my students play with this concept to see how it works. I was struck with
one thing. Although the concept of push and pull is relatively easy to
understand, it is challenging to achieve...a point that is made in the
interactive, online game. So doing abstract art is not that easy after all :-)