Here is a great form to use to help your kiddos remember the order for rainbow writing. I simply print several copies, laminate them and hang them on the wall. Whenever my kids do rainbow writing they know exactly where to go to get a rainbow writing sheet so they know the order of the colors!
This download contains a sheet with two rainbow writing orders on itl. Each color word is written in the color to help students connect the word with its color. Hope this helps your students when it comes to rainbow writing!!