Geranium 'Biokovo' has a pink tint, due to the pink stamens
Penstemon 'Husker Red' has both green and burgandy tints
Corydalis ochroleuca with green centers.
This hydrangea macrophylla opens greenish, my favorite kind of white.
Star jasmine which is not jasmine, but properly named Trachelospermum jasminoides.
Calla lily, not a lily but Zantedeschia
Just opening, 'White Swan' echinacea. The center cones eventually turn a deep copper.
Lychnis coronaria alba, too white with pale gray foliage, looks out of place.