The different colors and perfumes that has flowers are not random, but serve specific functions. The flowers are pollinated by insects and they do need to get them through a food produced in the deepest part of the corolla: the nectar. To take an insect lands on the petals and look for this food. Meanwhile, his body touches the anthers and pollen grains will adhere, then take you to another flower of the same species to find nectar in the same flavor. Therefore, the flowers have to be visible from a distance, through showy blossoms and scents that animals can be distinguished. There are flowers that attract a single species of insects because they have a special taste, like sage which has been adapted, through its form, so that only the bees can pollinate.
The hummingbird pollinating many species of orchids. For nectar in the flower introduces its long beak, and full of pollen that gets transferred to another orchid.
There are flowers that are ready for insects at night and give off their scent at night.