I am on a milkcap run right now. They are great free learning! I made this game way to difficult for Adeline but I wanted to have it done so that she could grow into it.
For this activity I used milkcaps and paint chips from a paint department. You will need two chips of the same color, one for the cap the other for matching. I cut circles out and glue guned them onto the lid.
You can start however simple or difficult your child needs. I used about six colors with Adeline.