How does Charon’s surface differ from Pluto’s surface?

The surface of Charon differs significantly from that of Pluto in both composition and reflectivity.12

• Composition: Charon’s surface is covered primarily by water ice, whereas Pluto’s surface is characterized by a prevalence of frozen methane, as well as nitrogen and carbon monoxide ices. Additionally, Charon’s surface features patches of ammonia in some impact craters, a component not noted as a primary constituent of Pluto's surface.312
• Reflectivity: Charon is less reflective than Pluto, possessing a lower average albedo of approximately 0.25 to 0.35, compared to Pluto’s average albedo of 0.72. This lower reflectivity suggests that Charon’s surface contains darker materials, such as cometary dust.312
• Color: Charon is described as being more neutral in color compared to the varied, often darker, and reddish-hued regions found on Pluto, such as the tholin-rich Cthulhu Regio.32