Heat sinks, often black anodized aluminum, feel cold to the touch due to their effective heat conductivity, which allows them to transfer heat away from the fingers and distribute it across their surface. While black surfaces absorb more wavelengths of light, they also radiate heat more efficiently when warmer than their surroundings, making them suitable for use in electronics. In contrast, shiny surfaces reflect light and may not dissipate heat as effectively in indoor environments. The discussion also touches on the Crookes radiometer, illustrating principles of heat absorption and radiation, but emphasizes that the primary function of heat sinks relies on convection rather than radiation. Overall, the black anodization serves both aesthetic and functional purposes in enhancing heat dissipation in electronic devices.