Use InfillBlur for tasks where you must replace a section of an image with a uniform colour. The InfillBlur Matchbox fills the area defined by the Selective Matte with the diffuse colour from outside that area. Works best with uniform diffuse colours.
To use the InfillBlur Matchbox:
The GMask fills with the colour outside the GMask.
The Colour menu controls the exposure, contrast, and saturation of the infill result. Use these controls to match the surrounding colour.