Looking at these together I would probably not plant Beverly Sills in with the group. It's a beautiful iris...I would just plant it separately.
There are others who are really great at color combinations. I might look for an orange to go in with them.
Here is a link to a great article about color coordinating your irises. It has some beautiful collages including two that are in the same color scheme as the irises you are looking at. I think they may give you some ideas of what would look nice with Dr Who and Toronto.
