I have a cake to do that includes fall coloured flowers and i thought i would do a deep pink Peony with some Burnt orange roses and dark purple roses or Cala Lily's. Not sure if the peony would be too spring like for a cake.
My first thought? I don't think of peonies as fall flowers.
Mums and asters? Definitely fall flowers. I'd keep the burnt orange/burnt yellow/light brown fall theme and have the purple calla lilies as an accent. I think it would look gorgeous!
Mums come in wonderful fall colours like rust, orange, purple, as well as creamy white. They are easy to make out of royal icing.
Hydrangeas that have turned rusty pink are fall flowers also. Just use more dust on the regular flowers.
NO PEONIES for a fall cake.