Bomber jackets, or flight jackets, got their start keeping fighter pilots warm during World War I, and with a heritage like that, they can’t be anything but cool.
They have, however, come a long way since then. They are now lighter weight, not the heavily insulated jackets of old, and more of a fashion piece than utilitarian. You can find more traditional looking ones, worn leather, with a looser shape, but generally the term “bomber jacket” has come to refer to most collarless jackets, with a loose shape (varsity jackets are similar).
In recent years bombers have become the staple style of jacket for brighter colors and wilder patterns, but it works in almost any configuration. Solid colors, sleeves that are a different color, varsity stripes on the collar, it pretty much all works.
They also pair with almost all looks, from semi-formal to casual, so they can be thrown over most things.