Since medieval times, the color yellow has been associated in Western culture with cowardice and treachery. This started with the perspective that our health was governed by 4 humors: blood, phlegm, black bile and yellow bile. Too much of any one humor created imbalance, and too much yellow bile supposedly made one peevish, unreliable, and vindictive.
This led to many condemning usages of the color; from painting Judas Iscariot (the classic traitor) in yellow, to dabbing yellow paint onto the doors of suspected traitors in France, to dressing victims of the Inquisition in yellow, and inventing the term "yellow-bellied" to indicate cowardice.
Ironically, in Eastern cultures and many religions, yellow is the life-giving color of the sun and symbolizes brilliance, intelligence, high worth, and clarity. We see this when someone successful is referred to as "golden".
Why such divergent perspectives? Metaphysically, embracing and wearing the color yellow means embracing logic and pragmatism. It's easy to see how, in an emotional situation (say a response to a political insult), a person calling for logic and reason could be considered unpatriotic and treasonous for a less than hot-blooded response to a threat. Humans are quick to rise to insult and fiercely protective as a rule; often ruled by hearts and gut-level instincts rather than heads.
Where do you fall on the yellow spectrum? In this time of great political division, it may be useful to consider.