Bonnie, I bet that lack of white in Iris beds is because there are so many muted colors among Irises, and bright sparkling white makes them look dirty. I have a handful of whites that I use in various spots around the garden, one I love has big, bright, orange beards and I've planted orange Poppies nearby. Another I love is lacy and ruffled (I think it is Laced Cotton) that grows in beds among blues and yellows.
Sue, that garden has a lot of the same plants I use in my bed of fire colors. It's interesting to watch it develop in spring, first it's all the bulb plants, clear yellows, oranges, and reds from Daffodils and Tulips, and some white (from white/orange Daffs)- all very sparkly and bright. Then as late spring comes, the colors deepen when Irises and foliages start shining, and the overall look becomes autumnal, then it brightens up again with early summer flowers- Lilies, Daylilies, Coreopsis, etc. In fall I worked on incorporating some bright pops of reds, golds, and oranges (red and orange Poppies, orange flowering Quince, red azalea) to the late spring display, and removed the 'Firecracker' Lysimachia that I liked a lot, but it had become a thug. I would like to find some other red/gold/bronze foliage accents that are well behaved and can offer some height.
Linnea, I'm so going to steal that term "intuitive mess"! LOL Very much describes me too! I start with broad plan, then let intuition guide my hand, ...and then do a lot of moving things around. I'm glad you mentioned Calendula, I used to grow them and loved that early display with the later Irises!