Make barracks out of gold and they will get dull quickly. Gold is soft, it's okay for jewelry and delicate things that aren't used much, but barracks for soldiers? Those are used constantly, and they get worn out easily. What was once shiny gold will go dull in days.
As you stare sadly at the dull barracks, the don (どん) shows up out of nowhere, and he's pissed. He turns his angry gaze toward you and says, "How did my barracks get so dull? Are you at fault? This is bad, this is very bad. Someone will pay for this."
Currently there are no similar looking kanji which exist in the WaniKani learning system