Initially, LiveMatte removes a specific color from the foreground image. This color is chosen using the Color button. To choose this key color, click on the Color sample box and keep the mouse button depressed. Drag the eyedropper tool over one of the video monitors to choose the color you wish to remove and then release it. The neighboring ‘color well’ is updated to show the color selected.
Hint: Enable the Lumakey switch to disregard hue, and base the effect solely on luminance.