I like blue with peach. I am not sure which blue flowers would work for you - forget me not, columbine, salvia, delphineum, morning glories, blue hosta, campanula, aster, false indigo-baptista, cranesbill geranium, catmint, penstemon, lobelia, scabiosia, veronica, viola, cornwall blue butterfly bush, bluebird hibiscus, hydrangea.
Guess who else has been looking for blue companions for peach and yellow roses.
Heuchera may look nice. I like bright green or chartreuse leaves in shade.
