As with most night flowering plants the flowers are white ,as they are pollinated by moths and other night flying insects this makes them more easilly seen.
Because at night there is less light, so the chlorophyll inside the plant does not give of enough wave lengths of green, so the plant in result turns out less colorful.
Flowers polinated by moths...
The Night Blooming Cereus aka the Dutchmans Pipe Cactus appears to bloom under distress. I have a plant that is 96 + years old - obviously passed down in the family :) and have noticed that if I sit...