Question

why do some plants have bright coulors and sweet smells

Answer 1

bright color is due chlorophyll is more and i tend to think pollination is the preserve of bees, but many different animals provide this service to plants including other insects (moths, wasps, hoverflies and beetles), bats, birds, mice and even lizards. For many, the flower’s smell will be critical in indicating where the plant is and when it's ready to be pollinated – which will often coincide with when it is offering its nectar or pollen reward is the reason for smell

Answer 2

it is because they are insect pollinated plants. in otder to attract the insects they produce nectar and are bright present in groups.