That's right! There are four houses, and they all belong to a magical school where wizards and witches are taught how to use their magic. People outside of the stories tend to identify with the houses even if they don't have magic. [since she can predict his protest there]
The four houses are called Gryffindor, Slytherin, Hufflepuff, and Ravenclaw! [She points to examples of each set of colors in the room as she says each name] And each house has particular traits and values favored above all others. Gryffindors are known for their courage, chivalry, determination, and their strong will!