Snow appears white because it’s made of countless tiny ice crystals with many surfaces. Each crystal refracts and reflects incoming light at different angles. As light passes between crystals, it undergoes multiple scattering events. This process reflects nearly all visible wavelengths equally. When all wavelengths are scattered back to our eyes at once, we perceive white. A single ice crystal is transparent, but many together randomize light directions. This is an example of diffuse reflection rather than specular reflection. The structure of snow maximizes scattering efficiency. If light absorption increases (like with dirt), snow looks darker.