We used a clear plastic egg tray and I gave her a bowl with a mix of pom poms and buttons in six different colours. Munchkin sat next to her and explored the different pom poms. He especially liked the small pom poms because they had tinsel string in them, so they were shiny. Bean was able to identify all of the colours (blue, pink, orange, purple, yellow, and red) and showed Munchkin where each colour went. He kept rearranging the materials, so Bean had to keep on her toes to match them :)
To make it a little easier for Munchkin, we used clear bowls with construction paper glued to the bottom of them in each of the colours we were using.