Remove Color Matting

The Remove Color Matting effect removes color fringes from layers that are premultiplied with a color. It is useful when merging alpha and fill from separate files. If you import footage with a premultiplied alpha channel or if you create alpha channels with After Effects, you may need to remove halos from an image. Halos are caused by a large contrast between the image's color and the background, or matte, color. Removing or changing the color of the matte can remove the halos. (Halos can also be caused by a misinterpretation of an alpha channel's premultiplied color.)

Use Background Color to specify the new background color when you want to change the color of a matte.


Original premultiplied with black (left), the black halo (center), and after applying the Remove Color Matting effect to remove the halo (right)

Use this effect in conjunction with other effects that let you create alpha channels, to achieve more control over the appearance of the alpha channel.


Original (left); with Channel Shift effect applied to create alpha channel from the red channel (center); and with Remove Color Matting applied twice: once with cyan selected, once with yellow selected (right)