Which of the following beer qualities is least likely to be affected by the addition of hops?

The quality of beer that is least likely to be affected by the addition of hops is color. Hops primarily contribute to the aroma, bitterness, and flavor of beer due to the alpha acids and essential oils they contain. The bitterness comes from the alpha acids that are extracted during the boiling process, while the aromatic oils provide a distinct aroma and enhance the flavor profile of the beer.

Color, however, is primarily influenced by the malt used in the brewing process rather than by hops. The type of malt—such as pale malt, caramel malt, or roasted malt—determines the color of the beer, and while hops might impart some slight nuances to the overall hue because of their compounds, they do not significantly change the base color contributed by the malt. Thus, when considering the roles of hops in brewing, it is clear that they affect aroma, bitterness, and flavor much more than they do color.