Question

Why are night-blooming flowers generally white?

Answer 1

Most pollinators only fly during the day, thus most flowers open when the sun shines to accommodate their pollinators, pollinators such as moths only fly at night, forcing the flowers they pollinate to modify their timetable. This is also why flowers that bloom at night are usually in a lighter colour scheme.

Complete answer:
Because they don't have to expend resources secreting coloured pigments to be visible to insects at night, night blooming flowers are usually white, and the white colour refracts light, making them visible for pollination.
Night-blooming plants are often white, but have a pleasant odour, as insects cannot see at night but are attracted to their scent. White is a good light reflector and a hue that a variety of pollinators prefer to view at night. White flowers blossom at night, as a result.
Bees use their senses of sight and smell to find nectar. The forager bee will land inside the blossom or near it. The bee will use her proboscis, which is comparable to a tongue, once she has landed on or near the bloom. She stretches it into the nectar-producing portion of the flower.
The antennae of bees are used to detect odours. They can also sense spatially thanks to the antennae's mobility, allowing them to discern which direction the fragrance is coming from, allowing them to head right for the blossoming plant, pollinate it, and gather the nectar.
The nectar, which is the basis for honey, is sucked up by the bees' proboscis and stored in their honey stomach. Pollen, which is high in protein and required mostly for brood rearing, is taken up by bees virtually as they fly by. It adheres to the bees' hairs, and when they visit another plant of the same species, it is transferred to their stigma in sufficient quantities.

Note:-
Evening Primrose (Oenothera biennis) is a plant of the Onagraceae family that is native to North America but has since spread to Europe, Asia, New Zealand, and Australia. Evening Primrose is the name given to a lovely yellow flower that blooms exclusively at night. The herb is well-known for its medicinal properties.