Blue Screening is basically the same as Green Screening as they are both special kinds of compositing with each using the screen indicated by their names. Blue screen, also known as chroma key is a technique used to mix two images together wherein a color or a small color range from one image is removed or made transparent to reveal another image behind it.

Most commonly used in weather forecasting broadcasts, the presenter appears to be standing in front of a large map which is actually a large blue or green background. Blue and green are considered the colors that are least like skin tone which explains the preference for them, while red is usually avoided due to its prevalence in normal human skin pigments. Green appears to be the most favored color at present since digital cameras retain more detail in green channel and requires less light than blue.