I think its because flowers were created to catch people's attention,so if they don't have the bright colours and even the sweet smell there won't be any need for them to be there because they won't be recognised.
It's to attract birds and insects so that they can spread their seeds and increase their population!
nectar
Flowers attract insects by: Big and colourful petals. Sweet scented. By nectar.
Color, shape, odor, and taste. For example, honeybees are attracted to bright colors, open-petal-shaped flowers, flowers which have certain smells, and the sweet nectar produced by many flowers. They can even be "trained" to pollinate flowers which humans might not find particularly attractive such as onion (allium spp.) flowers.
the colors, maybe even the smells can capture a childs attention
Many flowers, like the hibiscus have evolved to attract insects by traits such as bright colors and attractive smells.
There are two major plant adaptations that flowers employ to assist in pollination. The color of petals and bracts are attractive to the necessary insects and the smell helps attract the insects that will ferry the pollen to the next flower.
i think its were the flower grows into the beautiful petals and eventually dies and starts the stage again. Flower growth continues after its opening till the fruit is formed from its ovary
fresh air and flowers
Moths attracts mates through smells (pheromones) and butterflies attract mates visually (some butterfly colors reflect UV light). Also, many butterflies are poisonous to birds - the bright colors are an evolutionary adaptation to warn potential predators that eating them will do them no good, just like how many poisonous frogs are bright orange or red, striped, etc. The moth has the most sensitive sense of smell on any animal known to science.
Sights: Vibrant colors of flowers, green grass, and blue skies. Smells: Freshly cut grass, blooming flowers, and sunscreen. Sounds: Birds chirping, waves crashing, and children playing. Tastes: Ice-cold watermelon, grilled BBQ, and sweet iced tea.
The smells in flowers come from special oils that are produced in the petals as the plant grows. When this oil evaporates, which it does very easily, it gives off a fragrance which we can smell. Various combinations of chemicals in the oils of different flowers result in a variety of fragrances. Some are pleasant, sweet smells, like those of roses, lilacs, and lilies, while others are quite unpleasant. The pelican flower of South America, for example, smells like rotten meat! Flowers get their red, purple, orange, pink, or yellow colors from the pigments, or coloring matter, in the sap of their cells. It is both the scents and colors which attract insects and birds, which land on the flower to sip its nectar. In doing so, they help to spread the pollen for new flowers. Many flowers have the same oil in their leaves, roots, and fruit as they have in their petals, so we can smell the fragrances in those places too!
but smells like flowers