Agreed Ron, and to put it the other way arround, the presence of the pigments for the flowers can show up in stems and leaves as well as just the flowers.
My example one, while a white flower has the purple pigment for the purple pattening on the flower. The slight oddity is that it has such little colour in the flower but shows it strongler than all my others in the stem... although maybe that's NOT odd, maybe the stem is holding back a lot of the pigment and less of it gets to the flower...
