Ties are the most pointless piece of clothing and have no practical purpose. If you want some color get a nice colored shirt.
And for the practicality I find myself half freezing to death this time a year when I walk to work without a tie (around 45°F/8°C with brisk winds). Having a tie efficiently blocks the wind from entering the chest area through the button seams and around the neck without requiring me to bring a bulky scarf (which is very unpleasant in the afternoon when temperatures have risen to about 70°F/21°C.
That's why they invented this thing called a "jacket".