A swallowtail is a type of flag with a cutout on the right "fly" side, typically used on maritime flags. I used the swallowtail shape to reflect Seattle's seafaring history.

The teal is taken directly from the current flag, and represents the Seattle skies and waters, as well as the Indigenous history of the city.
The white represents the mountains surrounding the city, as well as the bright future brought by Seattleites.
The green represents the hills of Seattle and the natural beauty of the city.

A literal theme for the Emerald City, the emerald gemstone also abstracts the shape of Seattle's isthmus between the dark salt water of the Salish Sea and the light fresh water of Lake Washington.

This flag for Washington state depicts green forests and the blue of the Columbia River (aka Wimal.)
The three white peaks represent the Olympic Mountains of Western Washington, the Okanogan Highlands of Eastern Washington, and the Cascades along the state's center.
The three stars come from the arms of the state's namesake, but are changed to a pinker shade to represent the state flower (the rhodendron) and the state fish (the rainbow trout.) One version rotates them 47.7511°, the average latitude of Washington state.

The flag's elements are designed to pair harmoniously but distinctively with the U.S. flag, the Cascadian flag, my 2018 Seattle flag design, and this gorgeous flag concept by Douglas Lynch for our neighbors to the south.