Here's a simple project with big results to teach colors. Take a sheet of paper and fold it in half. On each side put a different color of paint. Be sure to put the paint on thickly in "blobs" rather than painting it thinly all over. Fold the paper and press down firmly and rub all over. When the paper is opened there will be beautiful "butterflies" of a third color. I drew antennae on the butterflies and wrote the "new" color name at the bottom. I've done this with a range of ages and it's always a big hit. Kids will make these over and over. They can't wait to open the paper and see what their butterflies look like!