Cant answer the title of the post, but for the description, Vexillology (The study of flags) has a general set of rules/guidelines on what makes a “Good” flag, and Washington’s flag fails a lot of them. CGP Grey has made a few videos talking about Vexillology and US state flags over the past couple of years that picked up a bunch of traction and got a bunch of people into vexillology which is why there have been pushes to change a bunch of the state flags somewhat recently.