Its interesting because I have a lily which is a varient or chance seedling of Capensis, out of a field in China, much like N. capensis var zanzibariensis rosea (IWC- Tropical day bloomers, Species Waterlilies) which is exactly the same colour as Miami Rose except it doesn't fade in colour third day and the sepals are different being blood red, its also of course fertile.
It has enough petals but it doesn't burn at all. So I have to think that to a certain extent substance has been compromised in N. miami r' as the colour isn't the cause.