The pattern called for 5 colors. I used black, white, grey, and Zebra Red Heart Super Saver yarns. For the 5th color I used Red Heart Super Saver Windsor Blue which was grey-ish enough to blend in.
This was a project I put together for my intermediate class that wanted to do a “more challenging” afghan. They had fun making their own color combinations.
I added a chart to the pattern so they could write down the colors and keep track of which square used which color/combo. Email me if you want a copy.