Brassiness, which refers to the color or tone of something being yellowish or golden, has a few antonyms that can describe opposite hues. One of them is pallor, which represents a lack of color or paleness. Another antonym for brassiness is coolness, which signifies a blue or green tinge in color. Similarly, silverness can connote a silver or gray undertone to a color, which is the opposite of brassiness. Additionally, one can use the antonym subtlety, which conveys a more muted or gentle quality that is the opposite of brassy brightness. By using these antonyms, one can create a fuller and more nuanced description of color and tone.