When you apply a blur node to a proxy clip in the Color FX room, and increase the diffuse value of the blur, the dark border effect will appear around the edges of the frame.
Programs
Color 1.5
Solution
To solve this problem, click the Geometry Room tab or by pressing (Command + 6). Then click the Pan & Scan tab and use the 'Scale parameter' slider to zoom in on the image until the border is cut off.
