False Color imagery typically makes use of a measurement from near-visible infrared region along with two measurements from the visible region. In this example, TM band 4 is assigned to the red color, band 3 to green, and band 2 to blue. Due to the reflectance properties of chlorophyll, the infrared signal of vegetation is very strong compared to other surface features, a predominant red tone is visible when vegetation is present. Deeper tones of red indicate broad leaf and robust vegetation while lighter reds signify grasslands or sparse vegetation. Soils and rock outcroppings take on various hues, typically gray-blue or brown, depending on the reflectance properties of the feature.
Urban areas are typically blue.
SWIR color image is formed by use of a mid infrared region measurement, along with near-visible infrared, and a visible region measurement. In this example, TM band 7 is assigned to red, band 4 to green and band 3 to blue. This time vegetation, such as that in the mountains appears green. Again the near-visible infrared response is strong, but the color assigned is green instead of red as in the false color image. Purple and magenta hues result from high mid wave response which could provide the image analyst insight into moisture conditions.