Crochet Afgan Help!

I know this is a knitting site but I’m hoping someone has seen this before. My Grandmother had this pattern book that she lent out to a friend to copy and they never gave it back. She really loves it and can’t duplicate it or find it. She’s willing to buy the pattern if it’s in a book but I took a few pictures and told her I’d do my best.

The reason she can’t duplicate it is because those aren’t color changes in the same row…the rows actually step up and down. She can do the step up…something about 3 crochet or something but she can’t figure out the step down.