There's a newer version of Joseph's Coat called Jacob's Robe that is very much a multicolored rose.
Berris and Cream and Candyland are each pink and white striped.
Those three all do very well in fairly harsh conditions here in Kansas. One thing you can do to make a rose look even more multicolored is to plant a clematis next to it, and train it to climb through the rose.
I know there's other roses--maybe our database is searchable on that? I'll take a look, but just wait a bit, others will come up with some more climbers.