What makes dark chocolate turn lighter?

Dark Chocolate can turn lighter due to a few factors, including exposure to air, moisture, or heat, which can lead to the formation of a white film called "bloom." This occurs when cocoa butter rises to the surface and solidifies, often due to temperature fluctuations. Additionally, the chocolate may lighten in color as it ages or if it contains added ingredients that alter its hue. Lastly, the cocoa content can also influence the darkness of the chocolate, as lower cocoa percentages result in a lighter appearance.