Are there studies of floral arrangement preferences of dichromats?
Unfortunately I am not aware of any such studies. However, you might want to look at the website vischeck.com. It allows you to upload images and then see what they might look like to people with color vision deficiencies. While the rendered colors might not be accurate, it would at least let you see which colors become indistinguishable. By testing some images of floral arrangements you would be able to see if the various flowers contrast more or less, etc.
