RFFC stands for "receptive by function, feature, and class." In this activity, students receptively (non-verbally) identify/sort items by one of their features (color). This activity is often done with flashcards, and I wanted to add a fun train theme to the activity because many of my students love trains and vehicles.
This activity is free to download, and includes easy instructions on how to use it.
Download the activity here: http://www.positivelyautism.com/downloads/rffc_colors.pdf