Certified GKH Gardening Expert
They contain, both, female and male reproductive organs in the same flower! This makes pollination control rather difficult. You will have to do some work to find out which colors are dominant and which are recessive so you can avoid flooding a generation with irreversible dominant traits.
For selection to work, you will need to cut off the pollen bearing structures of one color and then pollinate that plant with pollen from another color, while ensuring that you only harvest seeds from that one bloom. You must ensure that all other blooms are cut away, and that this plant is in isolation, or you risk contamination from another flower's pollen.