Think of composite laminates just like your normal teeth, just like your normal teeth turn yellow when you drink tea or coffee. Composites get colored and even turn yellow over time from the tea and coffee you drink. The reason for the yellowing is completely the tea and coffee you drink. So, how do you clean normal teeth when this discoloration is cleaned? In composites, they are cleaned and shined with a cleaning process called polyture. Whatever color is used when making the composite, that color retains itself in the same way, it does not change color. White composites remain white, they do not change color in the same way, they just get dirty. Even if it is a dirty tooth, it is cleaned even if it is a composite laminate.