A couple of other things to keep in mind.
Searching for Red isn't going to yield very many results, at least in the bearded classes. Honestly, it probably returns more results than it should. There are a few bearded irises that are nearly red, but most are closer to being wine or burgundy colored and they are generally listed in the database under Wine. Some beardless iris, especially the Louisianas, are red. Or, at least closer to red than wine.
Also, the Flower Patterns field is most useful with Tall Bearded Iris. The further you get from TBs, the messier the whole subject gets. Even within the TBs, there is plenty of room for interpretation.