Limestone is typically white or light-colored, often with variations due to impurities and minerals. The color can range from cream to tan, gray, or even black, depending on the presence of certain minerals and organic materials. The primary mineral in limestone is calcite, which is usually white, but other minerals like dolomite, iron, and organic matter can introduce color variations. For instance, iron oxides can give limestone a reddish or brownish hue, while organic remains can lead to a darker color. The specific color of a particular limestone deposit is influenced by the geological history and the environment in which it was formed.

The color of limestone is a result of its geological composition and the processes that occur during its formation. Limestone is formed from the accumulation of calcium carbonate in marine environments, such as shallow seas and lakes. Over time, these deposits harden into rock. The presence of impurities and minerals during this process can lead to a variety of colors. For example, the presence of iron oxides can give the limestone a reddish or brownish color, while the presence of organic matter can lead to a darker color. Additionally, the type of sedimentary environment where the limestone was formed can also influence its color. Limestones from marine environments are often lighter in color, while those from freshwater environments may be darker.

According to the U.S. Geological Survey, the color of limestone can vary widely due to the diverse range of minerals and organic materials that can be present. For instance, the report "Limestone in the United States" by the USGS notes that the color of limestone can range from white to black, with many shades in between. This diversity in color is a testament to the complex geological processes that contribute to the formation of limestone. The specific color of a limestone deposit is a reflection of its unique geological history and the environmental conditions under which it was formed.